[PATCH v3 1/4] drm: Add struct drm_rect and assorted utility functions

[PATCH v3 1/4] drm: Add struct drm_rect and assorted utility functions

[ville.syrjala]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

struct drm_rect represents a simple rectangle. The utility
functions are there to help driver writers.

v2: Moved the region stuff into its own file, made the smaller funcs
    static inline, used 64bit maths in the scaled clipping function to
    avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
v3: Renamed drm_region to drm_rect, drm_region_clip to
    drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/Makefile   |   3 +-
 drivers/gpu/drm/drm_rect.c |  96 +++++++++++++++++++++++++++++++++
 include/drm/drm_rect.h     | 132 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 230 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_rect.c
 create mode 100644 include/drm/drm_rect.h

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 0d59b24..8f94018 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -12,7 +12,8 @@ drm-y       :=	drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \
 		drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \
 		drm_crtc.o drm_modes.o drm_edid.o \
 		drm_info.o drm_debugfs.o drm_encoder_slave.o \
-		drm_trace_points.o drm_global.o drm_prime.o
+		drm_trace_points.o drm_global.o drm_prime.o \
+		drm_rect.o
 
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
new file mode 100644
index 0000000..1ad4f5e
--- /dev/null
+++ b/drivers/gpu/drm/drm_rect.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2011-2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <drm/drm_rect.h>
+
+/**
+ * drm_rect_intersect - intersect two rectangles
+ * @r1: first rectangle
+ * @r2: second rectangle
+ *
+ * Calculate the intersection of rectangles @r1 and @r2.
+ * @r1 will be overwritten with the intersection.
+ *
+ * RETURNS:
+ * @true if rectangle @r1 is still visible after the operation,
+ * @false otherwise.
+ */
+bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
+{
+	r1->x1 = max(r1->x1, r2->x1);
+	r1->y1 = max(r1->y1, r2->y1);
+	r1->x2 = min(r1->x2, r2->x2);
+	r1->y2 = min(r1->y2, r2->y2);
+
+	return drm_rect_visible(r1);
+}
+EXPORT_SYMBOL(drm_rect_intersect);
+
+/**
+ * drm_rect_clip_scaled - perform a scaled clip operation
+ * @src: source window rectangle
+ * @dst: destination window rectangle
+ * @clip: clip rectangle
+ * @hscale: horizontal scaling factor
+ * @vscale: vertical scaling factor
+ *
+ * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
+ * same amounts multiplied by @hscale and @vscale.
+ *
+ * RETUTRNS:
+ * @true if rectangle @dst is still visible after being clipped,
+ * @false otherwise
+ */
+bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
+			  const struct drm_rect *clip,
+			  int hscale, int vscale)
+{
+	int diff;
+
+	diff = clip->x1 - dst->x1;
+	if (diff > 0) {
+		int64_t tmp = src->x1 + (int64_t) diff * hscale;
+		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+	diff = clip->y1 - dst->y1;
+	if (diff > 0) {
+		int64_t tmp = src->y1 + (int64_t) diff * vscale;
+		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+	diff = dst->x2 - clip->x2;
+	if (diff > 0) {
+		int64_t tmp = src->x2 - (int64_t) diff * hscale;
+		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+	diff = dst->y2 - clip->y2;
+	if (diff > 0) {
+		int64_t tmp = src->y2 - (int64_t) diff * vscale;
+		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+
+	return drm_rect_intersect(dst, clip);
+}
+EXPORT_SYMBOL(drm_rect_clip_scaled);
diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
new file mode 100644
index 0000000..40b09a4
--- /dev/null
+++ b/include/drm/drm_rect.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2011-2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef DRM_RECT_H
+#define DRM_RECT_H
+
+/**
+ * drm_rect - two dimensional rect
+ * @x1: horizontal starting coordinate (inclusive)
+ * @x2: horizontal ending coordinate (exclusive)
+ * @y1: vertical starting coordinate (inclusive)
+ * @y2: vertical ending coordinate (exclusive)
+ */
+struct drm_rect {
+	int x1, y1, x2, y2;
+};
+
+/**
+ * drm_rect_adjust_size - adjust the size of the rect
+ * @r: rect to be adjusted
+ * @x: horizontal adjustment
+ * @y: vertical adjustment
+ *
+ * Change the size of rect @r by @x in the horizontal direction,
+ * and by @y in the vertical direction, while keeping the center
+ * of @r stationary.
+ *
+ * Positive @x and @y increase the size, negative values decrease it.
+ */
+static inline void drm_rect_adjust_size(struct drm_rect *r, int x, int y)
+{
+	r->x1 -= x >> 1;
+	r->y1 -= y >> 1;
+	r->x2 += (x + 1) >> 1;
+	r->y2 += (y + 1) >> 1;
+}
+
+/**
+ * drm_rect_translate - translate the rect
+ * @r: rect to be tranlated
+ * @x: horizontal translation
+ * @y: vertical translation
+ *
+ * Move rect @r by @x in the horizontal direction,
+ * and by @y in the vertical direction.
+ */
+static inline void drm_rect_translate(struct drm_rect *r, int x, int y)
+{
+	r->x1 += x;
+	r->y1 += y;
+	r->x2 += x;
+	r->y2 += y;
+}
+
+/**
+ * drm_rect_downscale - downscale a rect
+ * @r: rect to be downscaled
+ * @horz: horizontal downscale factor
+ * @vert: vertical downscale factor
+ *
+ * Divide the coordinates of rect @r by @horz and @vert.
+ */
+static inline void drm_rect_downscale(struct drm_rect *r, int horz, int vert)
+{
+	r->x1 /= horz;
+	r->y1 /= vert;
+	r->x2 /= horz;
+	r->y2 /= vert;
+}
+
+/**
+ * drm_rect_width - determine the rect width
+ * @r: rect whose width is returned
+ *
+ * RETURNS:
+ * The width of the rect.
+ */
+static inline int drm_rect_width(const struct drm_rect *r)
+{
+	return r->x2 - r->x1;
+}
+
+/**
+ * drm_rect_height - determine the rect height
+ * @r: rect whose height is returned
+ *
+ * RETURNS:
+ * The height of the rect.
+ */
+static inline int drm_rect_height(const struct drm_rect *r)
+{
+	return r->y2 - r->y1;
+}
+
+/**
+ * drm_rect_visible - determine if the the rect is visible
+ * @r: rect whose visibility is returned
+ *
+ * RETURNS:
+ * @true if the rect is visible, @false otherwise.
+ */
+static inline bool drm_rect_visible(const struct drm_rect *r)
+{
+	return drm_rect_width(r) > 0 && drm_rect_height(r) > 0;
+}
+
+bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
+bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
+			  const struct drm_rect *clip,
+			  int hscale, int vscale);
+
+#endif
-- 
1.8.1.5

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[PATCH v3 2/4] drm: Add drm_rect_calc_{hscale, vscale}() utility functions

[ville.syrjala]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

These functions calculcate the scaling factor based on the source and
destination rectangles.

There are two version of the functions, the strict ones that will
return an error if the min/max scaling factor is exceeded, and the
relaxed versions that will adjust the src/dst rectangles in order to
keep the scaling factor withing the limits.

v2: Return error instead of adjusting regions, refactor common parts
    into one function, and split into strict and relaxed versions.
v3: Renamed drm_region to drm_rect, add "_rect_" to the function
    names.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/drm_rect.c | 177 +++++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_rect.h     |  12 +++
 2 files changed, 189 insertions(+)

diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
index 1ad4f5e..8270ab4 100644
--- a/drivers/gpu/drm/drm_rect.c
+++ b/drivers/gpu/drm/drm_rect.c
@@ -94,3 +94,180 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
 	return drm_rect_intersect(dst, clip);
 }
 EXPORT_SYMBOL(drm_rect_clip_scaled);
+
+static int drm_calc_scale(int src, int dst)
+{
+	int scale = 0;
+
+	if (src < 0 || dst < 0)
+		return -EINVAL;
+
+	if (dst == 0)
+		return 0;
+
+	scale = src / dst;
+
+	return scale;
+}
+
+/**
+ * drm_rect_calc_hscale - calculate the horizontal scaling factor
+ * @src: source window rectangle
+ * @dst: destination window rectangle
+ * @min_hscale: minimum allowed horizontal scaling factor
+ * @max_hscale: maximum allowed horizontal scaling factor
+ *
+ * Calculate the horizontal scaling factor as
+ * (@src width) / (@dst width).
+ *
+ * RETURNS:
+ * The horizontal scaling factor, or errno of out of limits.
+ */
+int drm_rect_calc_hscale(const struct drm_rect *src,
+			 const struct drm_rect *dst,
+			 int min_hscale, int max_hscale)
+{
+	int src_w = drm_rect_width(src);
+	int dst_w = drm_rect_width(dst);
+	int hscale = drm_calc_scale(src_w, dst_w);
+
+	if (hscale < 0 || dst_w == 0)
+		return hscale;
+
+	if (hscale < min_hscale || hscale > max_hscale)
+		return -ERANGE;
+
+	return hscale;
+}
+EXPORT_SYMBOL(drm_rect_calc_hscale);
+
+/**
+ * drm_rect_calc_vscale - calculate the vertical scaling factor
+ * @src: source window rectangle
+ * @dst: destination window rectangle
+ * @min_vscale: minimum allowed vertical scaling factor
+ * @max_vscale: maximum allowed vertical scaling factor
+ *
+ * Calculate the vertical scaling factor as
+ * (@src height) / (@dst height).
+ *
+ * RETURNS:
+ * The vertical scaling factor, or errno of out of limits.
+ */
+int drm_rect_calc_vscale(const struct drm_rect *src,
+			 const struct drm_rect *dst,
+			 int min_vscale, int max_vscale)
+{
+	int src_h = drm_rect_height(src);
+	int dst_h = drm_rect_height(dst);
+	int vscale = drm_calc_scale(src_h, dst_h);
+
+	if (vscale < 0 || dst_h == 0)
+		return vscale;
+
+	if (vscale < min_vscale || vscale > max_vscale)
+		return -ERANGE;
+
+	return vscale;
+}
+EXPORT_SYMBOL(drm_rect_calc_vscale);
+
+/**
+ * drm_calc_hscale_relaxed - calculate the horizontal scaling factor
+ * @src: source window rectangle
+ * @dst: destination window rectangle
+ * @min_hscale: minimum allowed horizontal scaling factor
+ * @max_hscale: maximum allowed horizontal scaling factor
+ *
+ * Calculate the horizontal scaling factor as
+ * (@src width) / (@dst width).
+ *
+ * If the calculated scaling factor is below @min_vscale,
+ * decrease the height of rectangle @dst to compensate.
+ *
+ * If the calculcated scaling factor is above @max_vscale,
+ * decrease the height of rectangle @src to compensate.
+ *
+ * RETURNS:
+ * The horizontal scaling factor.
+ */
+int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
+				 struct drm_rect *dst,
+				 int min_hscale, int max_hscale)
+{
+	int src_w = drm_rect_width(src);
+	int dst_w = drm_rect_width(dst);
+	int hscale = drm_calc_scale(src_w, dst_w);
+
+	if (hscale < 0 || dst_w == 0)
+		return hscale;
+
+	if (hscale < min_hscale) {
+		int max_dst_w = src_w / min_hscale;
+
+		drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);
+
+		return min_hscale;
+	}
+
+	if (hscale > max_hscale) {
+		int max_src_w = dst_w * max_hscale;
+
+		drm_rect_adjust_size(src, max_src_w - src_w, 0);
+
+		return max_hscale;
+	}
+
+	return hscale;
+}
+EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);
+
+/**
+ * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
+ * @src: source window rectangle
+ * @dst: destination window rectangle
+ * @min_vscale: minimum allowed vertical scaling factor
+ * @max_vscale: maximum allowed vertical scaling factor
+ *
+ * Calculate the vertical scaling factor as
+ * (@src height) / (@dst height).
+ *
+ * If the calculated scaling factor is below @min_vscale,
+ * decrease the height of rectangle @dst to compensate.
+ *
+ * If the calculcated scaling factor is above @max_vscale,
+ * decrease the height of rectangle @src to compensate.
+ *
+ * RETURNS:
+ * The vertical scaling factor.
+ */
+int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
+				 struct drm_rect *dst,
+				 int min_vscale, int max_vscale)
+{
+	int src_h = drm_rect_height(src);
+	int dst_h = drm_rect_height(dst);
+	int vscale = drm_calc_scale(src_h, dst_h);
+
+	if (vscale < 0 || dst_h == 0)
+		return vscale;
+
+	if (vscale < min_vscale) {
+		int max_dst_h = src_h / min_vscale;
+
+		drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);
+
+		return min_vscale;
+	}
+
+	if (vscale > max_vscale) {
+		int max_src_h = dst_h * max_vscale;
+
+		drm_rect_adjust_size(src, 0, max_src_h - src_h);
+
+		return max_vscale;
+	}
+
+	return vscale;
+}
+EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);
diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
index 40b09a4..164e6ce 100644
--- a/include/drm/drm_rect.h
+++ b/include/drm/drm_rect.h
@@ -128,5 +128,17 @@ bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
 			  const struct drm_rect *clip,
 			  int hscale, int vscale);
+int drm_rect_calc_hscale(const struct drm_rect *src,
+			 const struct drm_rect *dst,
+			 int min_hscale, int max_hscale);
+int drm_rect_calc_vscale(const struct drm_rect *src,
+			 const struct drm_rect *dst,
+			 int min_vscale, int max_vscale);
+int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
+				 struct drm_rect *dst,
+				 int min_hscale, int max_hscale);
+int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
+				 struct drm_rect *dst,
+				 int min_vscale, int max_vscale);
 
 #endif
-- 
1.8.1.5

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[PATCH v2 3/4] drm: Add drm_rect_debug_print()

[ville.syrjala]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Add a debug function to print the rectangle in a human readable format.

v2: Renamed drm_region to drm_rect, the function from drm_region_debug
    to drm_rect_debug_print(), and use %+d instead of +%d in the format.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/drm_rect.c | 22 ++++++++++++++++++++++
 include/drm/drm_rect.h     |  1 +
 2 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
index 8270ab4..ed19b77 100644
--- a/drivers/gpu/drm/drm_rect.c
+++ b/drivers/gpu/drm/drm_rect.c
@@ -24,6 +24,7 @@
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
+#include <drm/drmP.h>
 #include <drm/drm_rect.h>
 
 /**
@@ -271,3 +272,24 @@ int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
 	return vscale;
 }
 EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);
+
+/**
+ * drm_rect_debug_print - print the rectangle information
+ * @r: rectangle to print
+ * @fixed_point: rectangle is in 16.16 fixed point format
+ */
+void drm_rect_debug_print(const struct drm_rect *r, bool fixed_point)
+{
+	int w = drm_rect_width(r);
+	int h = drm_rect_height(r);
+
+	if (fixed_point)
+		DRM_DEBUG_KMS("%d.%06ux%d.%06u%+d.%06u%+d.%06u\n",
+			      w >> 16, ((w & 0xffff) * 15625) >> 10,
+			      h >> 16, ((h & 0xffff) * 15625) >> 10,
+			      r->x1 >> 16, ((r->x1 & 0xffff) * 15625) >> 10,
+			      r->y1 >> 16, ((r->y1 & 0xffff) * 15625) >> 10);
+	else
+		DRM_DEBUG_KMS("%ux%u%+d%+d\n", w, h, r->x1, r->y1);
+}
+EXPORT_SYMBOL(drm_rect_debug_print);
diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
index 164e6ce..d5d4e1c 100644
--- a/include/drm/drm_rect.h
+++ b/include/drm/drm_rect.h
@@ -140,5 +140,6 @@ int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
 int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
 				 struct drm_rect *dst,
 				 int min_vscale, int max_vscale);
+void drm_rect_debug_print(const struct drm_rect *r, bool fixed_point);
 
 #endif
-- 
1.8.1.5

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[PATCH v3 4/4] drm/i915: Implement proper clipping for video sprites

[ville.syrjala]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Properly clip the source when the destination gets clipped
by the pipe dimensions.

Sadly the video sprite hardware is rather limited so it can't do proper
sub-pixel postitioning. Resort to truncating the source coordinates to
(macro)pixel boundary.

The scaling checks are done using the relaxed drm_region functions.
That means that the src/dst regions are reduced in size in order to keep
the scaling factor within the limits.

Also do some additional checking against various hardware limits.

v2: Truncate src coords instead of rounding to avoid increasing src
    viewport size, and adapt to changes in drm_calc_{h,v}scale().
v3: Adapt to drm_region->drm_rect rename. Fix misaligned crtc_w for
    packed YUV formats when scaling isn't supported.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_sprite.c | 191 +++++++++++++++++++++++++++---------
 1 file changed, 145 insertions(+), 46 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 414d325..62e09d1 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -32,6 +32,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_rect.h>
 #include "intel_drv.h"
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
@@ -415,6 +416,20 @@ ilk_get_colorkey(struct drm_plane *plane, struct drm_intel_sprite_colorkey *key)
 		key->flags = I915_SET_COLORKEY_NONE;
 }
 
+static bool
+format_is_yuv(uint32_t format)
+{
+	switch (format) {
+	case DRM_FORMAT_YUYV:
+	case DRM_FORMAT_UYVY:
+	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_YVYU:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static int
 intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 		   struct drm_framebuffer *fb, int crtc_x, int crtc_y,
@@ -432,9 +447,28 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 	enum transcoder cpu_transcoder = intel_pipe_to_cpu_transcoder(dev_priv,
 								      pipe);
 	int ret = 0;
-	int x = src_x >> 16, y = src_y >> 16;
 	int primary_w = crtc->mode.hdisplay, primary_h = crtc->mode.vdisplay;
 	bool disable_primary = false;
+	bool visible;
+	int hscale, vscale;
+	int max_scale, min_scale;
+	int pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
+	struct drm_rect src = {
+		.x1 = src_x,
+		.x2 = src_x + src_w,
+		.y1 = src_y,
+		.y2 = src_y + src_h,
+	};
+	struct drm_rect dst = {
+		.x1 = crtc_x,
+		.x2 = crtc_x + crtc_w,
+		.y1 = crtc_y,
+		.y2 = crtc_y + crtc_h,
+	};
+	const struct drm_rect clip = {
+		.x2 = crtc->mode.hdisplay,
+		.y2 = crtc->mode.vdisplay,
+	};
 
 	intel_fb = to_intel_framebuffer(fb);
 	obj = intel_fb->obj;
@@ -450,19 +484,23 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 	intel_plane->src_w = src_w;
 	intel_plane->src_h = src_h;
 
-	src_w = src_w >> 16;
-	src_h = src_h >> 16;
-
 	/* Pipe must be running... */
-	if (!(I915_READ(PIPECONF(cpu_transcoder)) & PIPECONF_ENABLE))
-		return -EINVAL;
-
-	if (crtc_x >= primary_w || crtc_y >= primary_h)
+	if (!(I915_READ(PIPECONF(cpu_transcoder)) & PIPECONF_ENABLE)) {
+		DRM_DEBUG_KMS("Pipe disabled\n");
 		return -EINVAL;
+	}
 
 	/* Don't modify another pipe's plane */
-	if (intel_plane->pipe != intel_crtc->pipe)
+	if (intel_plane->pipe != intel_crtc->pipe) {
+		DRM_DEBUG_KMS("Wrong plane <-> crtc mapping\n");
 		return -EINVAL;
+	}
+
+	/* FIXME check all gen limits */
+	if (fb->width < 3 || fb->height < 3 || fb->pitches[0] > 16384) {
+		DRM_DEBUG_KMS("Unsuitable framebuffer for plane\n");
+		return -EINVAL;
+	}
 
 	/* Sprite planes can be linear or x-tiled surfaces */
 	switch (obj->tiling_mode) {
@@ -470,53 +508,111 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 		case I915_TILING_X:
 			break;
 		default:
+			DRM_DEBUG_KMS("Unsupported tiling mode\n");
 			return -EINVAL;
 	}
 
 	/*
-	 * Clamp the width & height into the visible area.  Note we don't
-	 * try to scale the source if part of the visible region is offscreen.
-	 * The caller must handle that by adjusting source offset and size.
+	 * FIXME the following code does a bunch of fuzzy adjustments to the
+	 * coordinates and sizes. We probably need some way to decide whether
+	 * more strict checking should be done instead.
 	 */
-	if ((crtc_x < 0) && ((crtc_x + crtc_w) > 0)) {
-		crtc_w += crtc_x;
-		crtc_x = 0;
+	max_scale = intel_plane->max_downscale << 16;
+	min_scale = intel_plane->can_scale ? 1 : (1 << 16);
+
+	hscale = drm_rect_calc_hscale_relaxed(&src, &dst, min_scale, max_scale);
+	BUG_ON(hscale < 0);
+
+	vscale = drm_rect_calc_vscale_relaxed(&src, &dst, min_scale, max_scale);
+	BUG_ON(vscale < 0);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip, hscale, vscale);
+
+	if (visible) {
+		/* check again in case clipping clamped the results */
+		hscale = drm_rect_calc_hscale(&src, &dst, min_scale, max_scale);
+		if (hscale < 0) {
+			DRM_DEBUG_KMS("Horizontal scaling factor out of limits\n");
+			drm_rect_debug_print(&src, true);
+			drm_rect_debug_print(&dst, false);
+			return hscale;
+		}
+
+		vscale = drm_rect_calc_vscale(&src, &dst, min_scale, max_scale);
+		if (vscale < 0) {
+			DRM_DEBUG_KMS("Vertical scaling factor out of limits\n");
+			drm_rect_debug_print(&src, true);
+			drm_rect_debug_print(&dst, false);
+			return vscale;
+		}
+
+		/* Make the source viewport size an exact multiple of the scaling factors. */
+		drm_rect_adjust_size(&src,
+				     drm_rect_width(&dst) * hscale - drm_rect_width(&src),
+				     drm_rect_height(&dst) * vscale - drm_rect_height(&src));
+
+		crtc_x = dst.x1;
+		crtc_y = dst.y1;
+		crtc_w = drm_rect_width(&dst);
+		crtc_h = drm_rect_height(&dst);
+
+		/*
+		 * Hardware doesn't handle subpixel coordinates.
+		 * Adjust to (macro)pixel boundary, but be careful not to
+		 * increase the source viewport size, because that could
+		 * push the downscaling factor out of bounds.
+		 */
+		src_x = src.x1 >> 16;
+		src_w = drm_rect_width(&src) >> 16;
+		src_y = src.y1 >> 16;
+		src_h = drm_rect_height(&src) >> 16;
+
+		if (format_is_yuv(fb->pixel_format)) {
+			src_x &= ~1;
+			src_w &= ~1;
+
+			/*
+			 * Must keep src and dst the
+			 * same if we can't scale.
+			 */
+			if (!intel_plane->can_scale)
+				crtc_w &= ~1;
+		}
 	}
-	if ((crtc_x + crtc_w) <= 0) /* Nothing to display */
-		goto out;
-	if ((crtc_x + crtc_w) > primary_w)
-		crtc_w = primary_w - crtc_x;
-
-	if ((crtc_y < 0) && ((crtc_y + crtc_h) > 0)) {
-		crtc_h += crtc_y;
-		crtc_y = 0;
+
+	/* Account for minimum size when scaling */
+	if (visible && (src_w != crtc_w || src_h != crtc_h)) {
+		BUG_ON(!intel_plane->can_scale);
+
+		/* FIXME interlacing min height is 6 */
+		/* FIXME return an error instead? */
+
+		if (crtc_w < 3 || crtc_h < 3)
+			visible = false;
+
+		if (src_w < 3 || src_h < 3)
+			visible = false;
 	}
-	if ((crtc_y + crtc_h) <= 0) /* Nothing to display */
-		goto out;
-	if (crtc_y + crtc_h > primary_h)
-		crtc_h = primary_h - crtc_y;
 
-	if (!crtc_w || !crtc_h) /* Again, nothing to display */
-		goto out;
+	/* Check size restrictions when scaling */
+	if (visible && (src_w != crtc_w || src_h != crtc_h)) {
+		unsigned int width_bytes = ((src_x * pixel_size) & 63) + src_w * pixel_size;
 
-	/*
-	 * We may not have a scaler, eg. HSW does not have it any more
-	 */
-	if (!intel_plane->can_scale && (crtc_w != src_w || crtc_h != src_h))
-		return -EINVAL;
+		BUG_ON(!intel_plane->can_scale);
 
-	/*
-	 * We can take a larger source and scale it down, but
-	 * only so much...  16x is the max on SNB.
-	 */
-	if (((src_w * src_h) / (crtc_w * crtc_h)) > intel_plane->max_downscale)
-		return -EINVAL;
+		if (src_w > 2048 || src_h > 2048 ||
+		    width_bytes > 4096 || fb->pitches[0] > 4096) {
+			DRM_DEBUG_KMS("Source dimensions exceed hardware limits\n");
+			return -EINVAL;
+		}
+	}
 
 	/*
 	 * If the sprite is completely covering the primary plane,
 	 * we can disable the primary and save power.
 	 */
-	if ((crtc_x == 0) && (crtc_y == 0) &&
+	if (visible &&
+	    (crtc_x == 0) && (crtc_y == 0) &&
 	    (crtc_w == primary_w) && (crtc_h == primary_h))
 		disable_primary = true;
 
@@ -540,11 +636,15 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 	if (!disable_primary)
 		intel_enable_primary(crtc);
 
-	intel_plane->update_plane(plane, fb, obj, crtc_x, crtc_y,
-				  crtc_w, crtc_h, x, y, src_w, src_h);
+	if (visible) {
+		intel_plane->update_plane(plane, fb, obj,
+					  crtc_x, crtc_y, crtc_w, crtc_h,
+					  src_x, src_y, src_w, src_h);
 
-	if (disable_primary)
-		intel_disable_primary(crtc);
+		if (disable_primary)
+			intel_disable_primary(crtc);
+	} else
+		intel_plane->disable_plane(plane);
 
 	/* Unpin old obj after new one is active to avoid ugliness */
 	if (old_obj) {
@@ -564,7 +664,6 @@ intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);
-out:
 	return ret;
 }
 
-- 
1.8.1.5

_______________________________________________
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dri-devel@lists.freedesktop.org
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Re: [PATCH v3 1/4] drm: Add struct drm_rect and assorted utility functions

[Laurent Pinchart]

Hi Ville,

Thanks for the patch.

On Wednesday 27 March 2013 17:46:22 ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> struct drm_rect represents a simple rectangle. The utility
> functions are there to help driver writers.
> 
> v2: Moved the region stuff into its own file, made the smaller funcs
>     static inline, used 64bit maths in the scaled clipping function to
>     avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
> v3: Renamed drm_region to drm_rect, drm_region_clip to
>     drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/Makefile   |   3 +-
>  drivers/gpu/drm/drm_rect.c |  96 +++++++++++++++++++++++++++++++++
>  include/drm/drm_rect.h     | 132 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 230 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/drm_rect.c
>  create mode 100644 include/drm/drm_rect.h
> 

[snip]

> diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> new file mode 100644
> index 0000000..1ad4f5e
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_rect.c
> @@ -0,0 +1,96 @@

[snip]

> +#include <linux/errno.h>
> +#include <linux/export.h>
> +#include <linux/kernel.h>
> +#include <drm/drm_rect.h>
> +
> +/**
> + * drm_rect_intersect - intersect two rectangles
> + * @r1: first rectangle
> + * @r2: second rectangle
> + *
> + * Calculate the intersection of rectangles @r1 and @r2.
> + * @r1 will be overwritten with the intersection.
> + *
> + * RETURNS:
> + * @true if rectangle @r1 is still visible after the operation,
> + * @false otherwise.

Isn't @ used for function parameters only ?

> + */
> +bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
> +{
> +	r1->x1 = max(r1->x1, r2->x1);
> +	r1->y1 = max(r1->y1, r2->y1);
> +	r1->x2 = min(r1->x2, r2->x2);
> +	r1->y2 = min(r1->y2, r2->y2);
> +
> +	return drm_rect_visible(r1);

Do callers always need that information, or should they instead call 
drm_rect_visible() explicitly when they need it ?

> +}
> +EXPORT_SYMBOL(drm_rect_intersect);
> +
> +/**
> + * drm_rect_clip_scaled - perform a scaled clip operation
> + * @src: source window rectangle
> + * @dst: destination window rectangle
> + * @clip: clip rectangle
> + * @hscale: horizontal scaling factor
> + * @vscale: vertical scaling factor
> + *
> + * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
> + * same amounts multiplied by @hscale and @vscale.
> + *
> + * RETUTRNS:
> + * @true if rectangle @dst is still visible after being clipped,
> + * @false otherwise
> + */
> +bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
> +			  const struct drm_rect *clip,
> +			  int hscale, int vscale)
> +{
> +	int diff;
> +
> +	diff = clip->x1 - dst->x1;
> +	if (diff > 0) {
> +		int64_t tmp = src->x1 + (int64_t) diff * hscale;
> +		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> +	}
> +	diff = clip->y1 - dst->y1;
> +	if (diff > 0) {
> +		int64_t tmp = src->y1 + (int64_t) diff * vscale;
> +		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> +	}
> +	diff = dst->x2 - clip->x2;
> +	if (diff > 0) {
> +		int64_t tmp = src->x2 - (int64_t) diff * hscale;
> +		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> +	}
> +	diff = dst->y2 - clip->y2;
> +	if (diff > 0) {
> +		int64_t tmp = src->y2 - (int64_t) diff * vscale;
> +		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> +	}
> +
> +	return drm_rect_intersect(dst, clip);
> +}
> +EXPORT_SYMBOL(drm_rect_clip_scaled);
> diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> new file mode 100644
> index 0000000..40b09a4
> --- /dev/null
> +++ b/include/drm/drm_rect.h
> @@ -0,0 +1,132 @@

[snip]

> +/**
> + * drm_rect - two dimensional rect
> + * @x1: horizontal starting coordinate (inclusive)
> + * @x2: horizontal ending coordinate (exclusive)
> + * @y1: vertical starting coordinate (inclusive)
> + * @y2: vertical ending coordinate (exclusive)

What's the rationale for making x2 and y2 exclusive ?

> + */
> +struct drm_rect {
> +	int x1, y1, x2, y2;
> +};
> +
> +/**
> + * drm_rect_adjust_size - adjust the size of the rect
> + * @r: rect to be adjusted
> + * @x: horizontal adjustment
> + * @y: vertical adjustment

What about renaming x and y to dx and dy ? It would make it more explicit that 
the adjustements are incremental and not absolute values.

> + * Change the size of rect @r by @x in the horizontal direction,
> + * and by @y in the vertical direction, while keeping the center
> + * of @r stationary.
> + *
> + * Positive @x and @y increase the size, negative values decrease it.
> + */
> +static inline void drm_rect_adjust_size(struct drm_rect *r, int x, int y)
> +{
> +	r->x1 -= x >> 1;
> +	r->y1 -= y >> 1;
> +	r->x2 += (x + 1) >> 1;
> +	r->y2 += (y + 1) >> 1;
> +}
> +
> +/**
> + * drm_rect_translate - translate the rect
> + * @r: rect to be tranlated
> + * @x: horizontal translation
> + * @y: vertical translation

dx and dy here too ?

> + *
> + * Move rect @r by @x in the horizontal direction,
> + * and by @y in the vertical direction.
> + */
> +static inline void drm_rect_translate(struct drm_rect *r, int x, int y)
> +{
> +	r->x1 += x;
> +	r->y1 += y;
> +	r->x2 += x;
> +	r->y2 += y;
> +}
> +
> +/**
> + * drm_rect_downscale - downscale a rect
> + * @r: rect to be downscaled
> + * @horz: horizontal downscale factor
> + * @vert: vertical downscale factor
> + *
> + * Divide the coordinates of rect @r by @horz and @vert.
> + */
> +static inline void drm_rect_downscale(struct drm_rect *r, int horz, int
> vert)

Shouldn't horz and vert be unsigned ?

> +{
> +	r->x1 /= horz;
> +	r->y1 /= vert;
> +	r->x2 /= horz;
> +	r->y2 /= vert;
> +}
> +
> +/**
> + * drm_rect_width - determine the rect width
> + * @r: rect whose width is returned
> + *
> + * RETURNS:
> + * The width of the rect.
> + */
> +static inline int drm_rect_width(const struct drm_rect *r)
> +{
> +	return r->x2 - r->x1;
> +}
> +
> +/**
> + * drm_rect_height - determine the rect height
> + * @r: rect whose height is returned
> + *
> + * RETURNS:
> + * The height of the rect.
> + */
> +static inline int drm_rect_height(const struct drm_rect *r)
> +{
> +	return r->y2 - r->y1;
> +}
> +
> +/**
> + * drm_rect_visible - determine if the the rect is visible
> + * @r: rect whose visibility is returned
> + *
> + * RETURNS:
> + * @true if the rect is visible, @false otherwise.
> + */
> +static inline bool drm_rect_visible(const struct drm_rect *r)
> +{
> +	return drm_rect_width(r) > 0 && drm_rect_height(r) > 0;
> +}
> +
> +bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
> +bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
> +			  const struct drm_rect *clip,
> +			  int hscale, int vscale);
> +
> +#endif
-- 
Regards,

Laurent Pinchart

Re: [PATCH v3 1/4] drm: Add struct drm_rect and assorted utility functions

[Ville Syrjälä]

On Thu, Apr 04, 2013 at 06:38:15PM +0200, Laurent Pinchart wrote:
> Hi Ville,
> 
> Thanks for the patch.
> 
> On Wednesday 27 March 2013 17:46:22 ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > struct drm_rect represents a simple rectangle. The utility
> > functions are there to help driver writers.
> > 
> > v2: Moved the region stuff into its own file, made the smaller funcs
> >     static inline, used 64bit maths in the scaled clipping function to
> >     avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
> > v3: Renamed drm_region to drm_rect, drm_region_clip to
> >     drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/Makefile   |   3 +-
> >  drivers/gpu/drm/drm_rect.c |  96 +++++++++++++++++++++++++++++++++
> >  include/drm/drm_rect.h     | 132 ++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 230 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/gpu/drm/drm_rect.c
> >  create mode 100644 include/drm/drm_rect.h
> > 
> 
> [snip]
> 
> > diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> > new file mode 100644
> > index 0000000..1ad4f5e
> > --- /dev/null
> > +++ b/drivers/gpu/drm/drm_rect.c
> > @@ -0,0 +1,96 @@
> 
> [snip]
> 
> > +#include <linux/errno.h>
> > +#include <linux/export.h>
> > +#include <linux/kernel.h>
> > +#include <drm/drm_rect.h>
> > +
> > +/**
> > + * drm_rect_intersect - intersect two rectangles
> > + * @r1: first rectangle
> > + * @r2: second rectangle
> > + *
> > + * Calculate the intersection of rectangles @r1 and @r2.
> > + * @r1 will be overwritten with the intersection.
> > + *
> > + * RETURNS:
> > + * @true if rectangle @r1 is still visible after the operation,
> > + * @false otherwise.
> 
> Isn't @ used for function parameters only ?

Not sure. It's been a while since I wrote these, and I guess I thought
that the @ was there just for higlighting purposes. Looks like the
documentation for the documentation system isn't that great :) so I
guess I'll need to try building the docs and see what happens.

> 
> > + */
> > +bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
> > +{
> > +	r1->x1 = max(r1->x1, r2->x1);
> > +	r1->y1 = max(r1->y1, r2->y1);
> > +	r1->x2 = min(r1->x2, r2->x2);
> > +	r1->y2 = min(r1->y2, r2->y2);
> > +
> > +	return drm_rect_visible(r1);
> 
> Do callers always need that information, or should they instead call 
> drm_rect_visible() explicitly when they need it ?

I suppose someone might call it w/o checking the visibility right away.
In my current use case I do use the return value, so it saves one line
of code :) But I don't mind changing it if you think that would be
better w/o the implicit drm_rect_visible() call.

> 
> > +}
> > +EXPORT_SYMBOL(drm_rect_intersect);
> > +
> > +/**
> > + * drm_rect_clip_scaled - perform a scaled clip operation
> > + * @src: source window rectangle
> > + * @dst: destination window rectangle
> > + * @clip: clip rectangle
> > + * @hscale: horizontal scaling factor
> > + * @vscale: vertical scaling factor
> > + *
> > + * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
> > + * same amounts multiplied by @hscale and @vscale.
> > + *
> > + * RETUTRNS:
> > + * @true if rectangle @dst is still visible after being clipped,
> > + * @false otherwise
> > + */
> > +bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
> > +			  const struct drm_rect *clip,
> > +			  int hscale, int vscale)
> > +{
> > +	int diff;
> > +
> > +	diff = clip->x1 - dst->x1;
> > +	if (diff > 0) {
> > +		int64_t tmp = src->x1 + (int64_t) diff * hscale;
> > +		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > +	}
> > +	diff = clip->y1 - dst->y1;
> > +	if (diff > 0) {
> > +		int64_t tmp = src->y1 + (int64_t) diff * vscale;
> > +		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > +	}
> > +	diff = dst->x2 - clip->x2;
> > +	if (diff > 0) {
> > +		int64_t tmp = src->x2 - (int64_t) diff * hscale;
> > +		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > +	}
> > +	diff = dst->y2 - clip->y2;
> > +	if (diff > 0) {
> > +		int64_t tmp = src->y2 - (int64_t) diff * vscale;
> > +		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > +	}
> > +
> > +	return drm_rect_intersect(dst, clip);
> > +}
> > +EXPORT_SYMBOL(drm_rect_clip_scaled);
> > diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> > new file mode 100644
> > index 0000000..40b09a4
> > --- /dev/null
> > +++ b/include/drm/drm_rect.h
> > @@ -0,0 +1,132 @@
> 
> [snip]
> 
> > +/**
> > + * drm_rect - two dimensional rect
> > + * @x1: horizontal starting coordinate (inclusive)
> > + * @x2: horizontal ending coordinate (exclusive)
> > + * @y1: vertical starting coordinate (inclusive)
> > + * @y2: vertical ending coordinate (exclusive)
> 
> What's the rationale for making x2 and y2 exclusive ?

I think exclusive makes things easier.

You don't have to add/subtract 1 when going between x1/x2 and x/w
representations. Based on some experience, it's surprisingly easy to
accidentally forget the 1 or add/subtract too many times when doing
this kind of conversions with inclusive end coordinates.

And especially with fixed point coordinates it's probably clearer that
say a rectangle with width 10 has coordinates x1=0.0x0000 x2=10.0x0000,
rather than x1=0.0x0000 x2=9.0xffff. IMHO the latter doesn't really
convey the fact that the edge is exactly at an integer coordinate.

> 
> > + */
> > +struct drm_rect {
> > +	int x1, y1, x2, y2;
> > +};
> > +
> > +/**
> > + * drm_rect_adjust_size - adjust the size of the rect
> > + * @r: rect to be adjusted
> > + * @x: horizontal adjustment
> > + * @y: vertical adjustment
> 
> What about renaming x and y to dx and dy ? It would make it more explicit that 
> the adjustements are incremental and not absolute values.

Good point. Or actually maybe they should be dw and dh.

> 
> > + * Change the size of rect @r by @x in the horizontal direction,
> > + * and by @y in the vertical direction, while keeping the center
> > + * of @r stationary.
> > + *
> > + * Positive @x and @y increase the size, negative values decrease it.
> > + */
> > +static inline void drm_rect_adjust_size(struct drm_rect *r, int x, int y)
> > +{
> > +	r->x1 -= x >> 1;
> > +	r->y1 -= y >> 1;
> > +	r->x2 += (x + 1) >> 1;
> > +	r->y2 += (y + 1) >> 1;
> > +}
> > +
> > +/**
> > + * drm_rect_translate - translate the rect
> > + * @r: rect to be tranlated
> > + * @x: horizontal translation
> > + * @y: vertical translation
> 
> dx and dy here too ?

Sure.

> 
> > + *
> > + * Move rect @r by @x in the horizontal direction,
> > + * and by @y in the vertical direction.
> > + */
> > +static inline void drm_rect_translate(struct drm_rect *r, int x, int y)
> > +{
> > +	r->x1 += x;
> > +	r->y1 += y;
> > +	r->x2 += x;
> > +	r->y2 += y;
> > +}
> > +
> > +/**
> > + * drm_rect_downscale - downscale a rect
> > + * @r: rect to be downscaled
> > + * @horz: horizontal downscale factor
> > + * @vert: vertical downscale factor
> > + *
> > + * Divide the coordinates of rect @r by @horz and @vert.
> > + */
> > +static inline void drm_rect_downscale(struct drm_rect *r, int horz, int
> > vert)
> 
> Shouldn't horz and vert be unsigned ?

Maybe. I'm actually not using this function currently (mainly because
our current hardware doesn't support planar formats) so I could just
remove the whole thing until it's needed.

> 
> > +{
> > +	r->x1 /= horz;
> > +	r->y1 /= vert;
> > +	r->x2 /= horz;
> > +	r->y2 /= vert;
> > +}
> > +
> > +/**
> > + * drm_rect_width - determine the rect width
> > + * @r: rect whose width is returned
> > + *
> > + * RETURNS:
> > + * The width of the rect.
> > + */
> > +static inline int drm_rect_width(const struct drm_rect *r)
> > +{
> > +	return r->x2 - r->x1;
> > +}
> > +
> > +/**
> > + * drm_rect_height - determine the rect height
> > + * @r: rect whose height is returned
> > + *
> > + * RETURNS:
> > + * The height of the rect.
> > + */
> > +static inline int drm_rect_height(const struct drm_rect *r)
> > +{
> > +	return r->y2 - r->y1;
> > +}
> > +
> > +/**
> > + * drm_rect_visible - determine if the the rect is visible
> > + * @r: rect whose visibility is returned
> > + *
> > + * RETURNS:
> > + * @true if the rect is visible, @false otherwise.
> > + */
> > +static inline bool drm_rect_visible(const struct drm_rect *r)
> > +{
> > +	return drm_rect_width(r) > 0 && drm_rect_height(r) > 0;
> > +}
> > +
> > +bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
> > +bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
> > +			  const struct drm_rect *clip,
> > +			  int hscale, int vscale);
> > +
> > +#endif
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Ville Syrjälä
Intel OTC

Re: [PATCH v3 1/4] drm: Add struct drm_rect and assorted utility functions

[Laurent Pinchart]

Hi Ville,

On Thursday 04 April 2013 22:52:37 Ville Syrjälä wrote:
> On Thu, Apr 04, 2013 at 06:38:15PM +0200, Laurent Pinchart wrote:
> > On Wednesday 27 March 2013 17:46:22 ville.syrjala@linux.intel.com wrote:
> > > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > 
> > > struct drm_rect represents a simple rectangle. The utility
> > > functions are there to help driver writers.
> > > 
> > > v2: Moved the region stuff into its own file, made the smaller funcs
> > > 
> > >     static inline, used 64bit maths in the scaled clipping function to
> > >     avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
> > > 
> > > v3: Renamed drm_region to drm_rect, drm_region_clip to
> > > 
> > >     drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
> > > 
> > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > ---
> > > 
> > >  drivers/gpu/drm/Makefile   |   3 +-
> > >  drivers/gpu/drm/drm_rect.c |  96 +++++++++++++++++++++++++++++++++
> > >  include/drm/drm_rect.h     | 132 ++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 230 insertions(+), 1 deletion(-)
> > >  create mode 100644 drivers/gpu/drm/drm_rect.c
> > >  create mode 100644 include/drm/drm_rect.h
> > 
> > [snip]
> > 
> > > diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> > > new file mode 100644
> > > index 0000000..1ad4f5e
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/drm_rect.c
> > > @@ -0,0 +1,96 @@
> > 
> > [snip]
> > 
> > > +#include <linux/errno.h>
> > > +#include <linux/export.h>
> > > +#include <linux/kernel.h>
> > > +#include <drm/drm_rect.h>
> > > +
> > > +/**
> > > + * drm_rect_intersect - intersect two rectangles
> > > + * @r1: first rectangle
> > > + * @r2: second rectangle
> > > + *
> > > + * Calculate the intersection of rectangles @r1 and @r2.
> > > + * @r1 will be overwritten with the intersection.
> > > + *
> > > + * RETURNS:
> > > + * @true if rectangle @r1 is still visible after the operation,
> > > + * @false otherwise.
> > 
> > Isn't @ used for function parameters only ?
> 
> Not sure. It's been a while since I wrote these, and I guess I thought
> that the @ was there just for higlighting purposes. Looks like the
> documentation for the documentation system isn't that great :) so I
> guess I'll need to try building the docs and see what happens.
> 
> > > + */
> > > +bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
> > > +{
> > > +	r1->x1 = max(r1->x1, r2->x1);
> > > +	r1->y1 = max(r1->y1, r2->y1);
> > > +	r1->x2 = min(r1->x2, r2->x2);
> > > +	r1->y2 = min(r1->y2, r2->y2);
> > > +
> > > +	return drm_rect_visible(r1);
> > 
> > Do callers always need that information, or should they instead call
> > drm_rect_visible() explicitly when they need it ?
> 
> I suppose someone might call it w/o checking the visibility right away.
> In my current use case I do use the return value, so it saves one line
> of code :) But I don't mind changing it if you think that would be
> better w/o the implicit drm_rect_visible() call.

I'm fine with whichever you think will be better. I just wanted to raise this 
point to make sure it has been thought about.

> > > +}
> > > +EXPORT_SYMBOL(drm_rect_intersect);
> > > +
> > > +/**
> > > + * drm_rect_clip_scaled - perform a scaled clip operation
> > > + * @src: source window rectangle
> > > + * @dst: destination window rectangle
> > > + * @clip: clip rectangle
> > > + * @hscale: horizontal scaling factor
> > > + * @vscale: vertical scaling factor
> > > + *
> > > + * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
> > > + * same amounts multiplied by @hscale and @vscale.
> > > + *
> > > + * RETUTRNS:
> > > + * @true if rectangle @dst is still visible after being clipped,
> > > + * @false otherwise
> > > + */
> > > +bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
> > > +			  const struct drm_rect *clip,
> > > +			  int hscale, int vscale)
> > > +{
> > > +	int diff;
> > > +
> > > +	diff = clip->x1 - dst->x1;
> > > +	if (diff > 0) {
> > > +		int64_t tmp = src->x1 + (int64_t) diff * hscale;
> > > +		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > > +	}
> > > +	diff = clip->y1 - dst->y1;
> > > +	if (diff > 0) {
> > > +		int64_t tmp = src->y1 + (int64_t) diff * vscale;
> > > +		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > > +	}
> > > +	diff = dst->x2 - clip->x2;
> > > +	if (diff > 0) {
> > > +		int64_t tmp = src->x2 - (int64_t) diff * hscale;
> > > +		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > > +	}
> > > +	diff = dst->y2 - clip->y2;
> > > +	if (diff > 0) {
> > > +		int64_t tmp = src->y2 - (int64_t) diff * vscale;
> > > +		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
> > > +	}
> > > +
> > > +	return drm_rect_intersect(dst, clip);
> > > +}
> > > +EXPORT_SYMBOL(drm_rect_clip_scaled);
> > > diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> > > new file mode 100644
> > > index 0000000..40b09a4
> > > --- /dev/null
> > > +++ b/include/drm/drm_rect.h
> > > @@ -0,0 +1,132 @@
> > 
> > [snip]
> > 
> > > +/**
> > > + * drm_rect - two dimensional rect
> > > + * @x1: horizontal starting coordinate (inclusive)
> > > + * @x2: horizontal ending coordinate (exclusive)
> > > + * @y1: vertical starting coordinate (inclusive)
> > > + * @y2: vertical ending coordinate (exclusive)
> > 
> > What's the rationale for making x2 and y2 exclusive ?
> 
> I think exclusive makes things easier.
> 
> You don't have to add/subtract 1 when going between x1/x2 and x/w
> representations. Based on some experience, it's surprisingly easy to
> accidentally forget the 1 or add/subtract too many times when doing
> this kind of conversions with inclusive end coordinates.
> 
> And especially with fixed point coordinates it's probably clearer that
> say a rectangle with width 10 has coordinates x1=0.0x0000 x2=10.0x0000,
> rather than x1=0.0x0000 x2=9.0xffff. IMHO the latter doesn't really
> convey the fact that the edge is exactly at an integer coordinate.
> 
> > > + */
> > > +struct drm_rect {
> > > +	int x1, y1, x2, y2;
> > > +};
> > > +
> > > +/**
> > > + * drm_rect_adjust_size - adjust the size of the rect
> > > + * @r: rect to be adjusted
> > > + * @x: horizontal adjustment
> > > + * @y: vertical adjustment
> > 
> > What about renaming x and y to dx and dy ? It would make it more explicit
> > that the adjustements are incremental and not absolute values.
> 
> Good point. Or actually maybe they should be dw and dh.

That's even better, yes.

> > > + * Change the size of rect @r by @x in the horizontal direction,
> > > + * and by @y in the vertical direction, while keeping the center
> > > + * of @r stationary.
> > > + *
> > > + * Positive @x and @y increase the size, negative values decrease it.
> > > + */
> > > +static inline void drm_rect_adjust_size(struct drm_rect *r, int x, int
> > > y)
> > > +{
> > > +	r->x1 -= x >> 1;
> > > +	r->y1 -= y >> 1;
> > > +	r->x2 += (x + 1) >> 1;
> > > +	r->y2 += (y + 1) >> 1;
> > > +}
> > > +
> > > +/**
> > > + * drm_rect_translate - translate the rect
> > > + * @r: rect to be tranlated
> > > + * @x: horizontal translation
> > > + * @y: vertical translation
> > 
> > dx and dy here too ?
> 
> Sure.
> 
> > > + *
> > > + * Move rect @r by @x in the horizontal direction,
> > > + * and by @y in the vertical direction.
> > > + */
> > > +static inline void drm_rect_translate(struct drm_rect *r, int x, int y)
> > > +{
> > > +	r->x1 += x;
> > > +	r->y1 += y;
> > > +	r->x2 += x;
> > > +	r->y2 += y;
> > > +}
> > > +
> > > +/**
> > > + * drm_rect_downscale - downscale a rect
> > > + * @r: rect to be downscaled
> > > + * @horz: horizontal downscale factor
> > > + * @vert: vertical downscale factor
> > > + *
> > > + * Divide the coordinates of rect @r by @horz and @vert.
> > > + */
> > > +static inline void drm_rect_downscale(struct drm_rect *r, int horz, int
> > > vert)
> > 
> > Shouldn't horz and vert be unsigned ?
> 
> Maybe. I'm actually not using this function currently (mainly because
> our current hardware doesn't support planar formats) so I could just
> remove the whole thing until it's needed.
> 
> > > +{
> > > +	r->x1 /= horz;
> > > +	r->y1 /= vert;
> > > +	r->x2 /= horz;
> > > +	r->y2 /= vert;
> > > +}
> > > +
> > > +/**
> > > + * drm_rect_width - determine the rect width
> > > + * @r: rect whose width is returned
> > > + *
> > > + * RETURNS:
> > > + * The width of the rect.
> > > + */
> > > +static inline int drm_rect_width(const struct drm_rect *r)
> > > +{
> > > +	return r->x2 - r->x1;
> > > +}
> > > +
> > > +/**
> > > + * drm_rect_height - determine the rect height
> > > + * @r: rect whose height is returned
> > > + *
> > > + * RETURNS:
> > > + * The height of the rect.
> > > + */
> > > +static inline int drm_rect_height(const struct drm_rect *r)
> > > +{
> > > +	return r->y2 - r->y1;
> > > +}
> > > +
> > > +/**
> > > + * drm_rect_visible - determine if the the rect is visible
> > > + * @r: rect whose visibility is returned
> > > + *
> > > + * RETURNS:
> > > + * @true if the rect is visible, @false otherwise.
> > > + */
> > > +static inline bool drm_rect_visible(const struct drm_rect *r)
> > > +{
> > > +	return drm_rect_width(r) > 0 && drm_rect_height(r) > 0;
> > > +}
> > > +
> > > +bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect
> > > *clip);
> > > +bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
> > > +			  const struct drm_rect *clip,
> > > +			  int hscale, int vscale);
> > > +
> > > +#endif
-- 
Regards,

Laurent Pinchart

Re: [PATCH v3 1/4] drm: Add struct drm_rect and assorted utility functions

[Ville Syrjälä]

On Fri, Apr 05, 2013 at 01:51:24AM +0200, Laurent Pinchart wrote:
> Hi Ville,
> 
> On Thursday 04 April 2013 22:52:37 Ville Syrjälä wrote:
> > On Thu, Apr 04, 2013 at 06:38:15PM +0200, Laurent Pinchart wrote:
> > > On Wednesday 27 March 2013 17:46:22 ville.syrjala@linux.intel.com wrote:
> > > > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > 
> > > > struct drm_rect represents a simple rectangle. The utility
> > > > functions are there to help driver writers.
> > > > 
> > > > v2: Moved the region stuff into its own file, made the smaller funcs
> > > > 
> > > >     static inline, used 64bit maths in the scaled clipping function to
> > > >     avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
> > > > 
> > > > v3: Renamed drm_region to drm_rect, drm_region_clip to
> > > > 
> > > >     drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
> > > > 
> > > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > ---
> > > > 
> > > >  drivers/gpu/drm/Makefile   |   3 +-
> > > >  drivers/gpu/drm/drm_rect.c |  96 +++++++++++++++++++++++++++++++++
> > > >  include/drm/drm_rect.h     | 132 ++++++++++++++++++++++++++++++++++++++
> > > >  3 files changed, 230 insertions(+), 1 deletion(-)
> > > >  create mode 100644 drivers/gpu/drm/drm_rect.c
> > > >  create mode 100644 include/drm/drm_rect.h
> > > 
> > > [snip]
> > > 
> > > > diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> > > > new file mode 100644
> > > > index 0000000..1ad4f5e
> > > > --- /dev/null
> > > > +++ b/drivers/gpu/drm/drm_rect.c
> > > > @@ -0,0 +1,96 @@
> > > 
> > > [snip]
> > > 
> > > > +#include <linux/errno.h>
> > > > +#include <linux/export.h>
> > > > +#include <linux/kernel.h>
> > > > +#include <drm/drm_rect.h>
> > > > +
> > > > +/**
> > > > + * drm_rect_intersect - intersect two rectangles
> > > > + * @r1: first rectangle
> > > > + * @r2: second rectangle
> > > > + *
> > > > + * Calculate the intersection of rectangles @r1 and @r2.
> > > > + * @r1 will be overwritten with the intersection.
> > > > + *
> > > > + * RETURNS:
> > > > + * @true if rectangle @r1 is still visible after the operation,
> > > > + * @false otherwise.
> > > 
> > > Isn't @ used for function parameters only ?
> > 
> > Not sure. It's been a while since I wrote these, and I guess I thought
> > that the @ was there just for higlighting purposes. Looks like the
> > documentation for the documentation system isn't that great :) so I
> > guess I'll need to try building the docs and see what happens.

I changed it to '%' since that's apparently meant for constants.

> > 
> > > > + */
> > > > +bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
> > > > +{
> > > > +	r1->x1 = max(r1->x1, r2->x1);
> > > > +	r1->y1 = max(r1->y1, r2->y1);
> > > > +	r1->x2 = min(r1->x2, r2->x2);
> > > > +	r1->y2 = min(r1->y2, r2->y2);
> > > > +
> > > > +	return drm_rect_visible(r1);
> > > 
> > > Do callers always need that information, or should they instead call
> > > drm_rect_visible() explicitly when they need it ?
> > 
> > I suppose someone might call it w/o checking the visibility right away.
> > In my current use case I do use the return value, so it saves one line
> > of code :) But I don't mind changing it if you think that would be
> > better w/o the implicit drm_rect_visible() call.
> 
> I'm fine with whichever you think will be better. I just wanted to raise this 
> point to make sure it has been thought about.

I left this as is for now. We can split it later if there's need for it.

<snip>
> > > > +/**
> > > > + * drm_rect_downscale - downscale a rect
> > > > + * @r: rect to be downscaled
> > > > + * @horz: horizontal downscale factor
> > > > + * @vert: vertical downscale factor
> > > > + *
> > > > + * Divide the coordinates of rect @r by @horz and @vert.
> > > > + */
> > > > +static inline void drm_rect_downscale(struct drm_rect *r, int horz, int
> > > > vert)
> > > 
> > > Shouldn't horz and vert be unsigned ?
> > 
> > Maybe. I'm actually not using this function currently (mainly because
> > our current hardware doesn't support planar formats) so I could just
> > remove the whole thing until it's needed.

I decided to leave the function as is. Using unsigned int for the
arguments would promote the numerator of the division to unsigned int
as well, and then the result would be wrong. So we'd either require
explicit casts to int, or we'd need to go with something like unsigned
short instead.

-- 
Ville Syrjälä
Intel OTC

[PATCH v4] drm: Add struct drm_rect and assorted utility functions

[ville.syrjala]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

struct drm_rect represents a simple rectangle. The utility
functions are there to help driver writers.

v2: Moved the region stuff into its own file, made the smaller funcs
    static inline, used 64bit maths in the scaled clipping function to
    avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
v3: Renamed drm_region to drm_rect, drm_region_clip to
    drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
v4: Renamed some function parameters, improve kernel-doc comments a bit,
    and actually generate documentation for drm_rect.[ch].

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 Documentation/DocBook/drm.tmpl |   2 +
 drivers/gpu/drm/Makefile       |   3 +-
 drivers/gpu/drm/drm_rect.c     |  96 ++++++++++++++++++++++++++++++
 include/drm/drm_rect.h         | 132 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 232 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_rect.c
 create mode 100644 include/drm/drm_rect.h

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index f9df3b8..7c7af25 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -1653,6 +1653,8 @@ void intel_crt_init(struct drm_device *dev)
     <sect2>
       <title>KMS API Functions</title>
 !Edrivers/gpu/drm/drm_crtc.c
+!Edrivers/gpu/drm/drm_rect.c
+!Finclude/drm/drm_rect.h
     </sect2>
   </sect1>
 
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 0d59b24..8f94018 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -12,7 +12,8 @@ drm-y       :=	drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \
 		drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \
 		drm_crtc.o drm_modes.o drm_edid.o \
 		drm_info.o drm_debugfs.o drm_encoder_slave.o \
-		drm_trace_points.o drm_global.o drm_prime.o
+		drm_trace_points.o drm_global.o drm_prime.o \
+		drm_rect.o
 
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
new file mode 100644
index 0000000..a9861bd
--- /dev/null
+++ b/drivers/gpu/drm/drm_rect.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2011-2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <drm/drm_rect.h>
+
+/**
+ * drm_rect_intersect - intersect two rectangles
+ * @r1: first rectangle
+ * @r2: second rectangle
+ *
+ * Calculate the intersection of rectangles @r1 and @r2.
+ * @r1 will be overwritten with the intersection.
+ *
+ * RETURNS:
+ * %true if rectangle @r1 is still visible after the operation,
+ * %false otherwise.
+ */
+bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
+{
+	r1->x1 = max(r1->x1, r2->x1);
+	r1->y1 = max(r1->y1, r2->y1);
+	r1->x2 = min(r1->x2, r2->x2);
+	r1->y2 = min(r1->y2, r2->y2);
+
+	return drm_rect_visible(r1);
+}
+EXPORT_SYMBOL(drm_rect_intersect);
+
+/**
+ * drm_rect_clip_scaled - perform a scaled clip operation
+ * @src: source window rectangle
+ * @dst: destination window rectangle
+ * @clip: clip rectangle
+ * @hscale: horizontal scaling factor
+ * @vscale: vertical scaling factor
+ *
+ * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
+ * same amounts multiplied by @hscale and @vscale.
+ *
+ * RETUTRNS:
+ * %true if rectangle @dst is still visible after being clipped,
+ * %false otherwise
+ */
+bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
+			  const struct drm_rect *clip,
+			  int hscale, int vscale)
+{
+	int diff;
+
+	diff = clip->x1 - dst->x1;
+	if (diff > 0) {
+		int64_t tmp = src->x1 + (int64_t) diff * hscale;
+		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+	diff = clip->y1 - dst->y1;
+	if (diff > 0) {
+		int64_t tmp = src->y1 + (int64_t) diff * vscale;
+		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+	diff = dst->x2 - clip->x2;
+	if (diff > 0) {
+		int64_t tmp = src->x2 - (int64_t) diff * hscale;
+		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+	diff = dst->y2 - clip->y2;
+	if (diff > 0) {
+		int64_t tmp = src->y2 - (int64_t) diff * vscale;
+		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+	}
+
+	return drm_rect_intersect(dst, clip);
+}
+EXPORT_SYMBOL(drm_rect_clip_scaled);
diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
new file mode 100644
index 0000000..2b7278c
--- /dev/null
+++ b/include/drm/drm_rect.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2011-2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef DRM_RECT_H
+#define DRM_RECT_H
+
+/**
+ * drm_rect - two dimensional rectangle
+ * @x1: horizontal starting coordinate (inclusive)
+ * @x2: horizontal ending coordinate (exclusive)
+ * @y1: vertical starting coordinate (inclusive)
+ * @y2: vertical ending coordinate (exclusive)
+ */
+struct drm_rect {
+	int x1, y1, x2, y2;
+};
+
+/**
+ * drm_rect_adjust_size - adjust the size of the rectangle
+ * @r: rectangle to be adjusted
+ * @dw: horizontal adjustment
+ * @dh: vertical adjustment
+ *
+ * Change the size of rectangle @r by @dw in the horizontal direction,
+ * and by @dh in the vertical direction, while keeping the center
+ * of @r stationary.
+ *
+ * Positive @dw and @dh increase the size, negative values decrease it.
+ */
+static inline void drm_rect_adjust_size(struct drm_rect *r, int dw, int dh)
+{
+	r->x1 -= dw >> 1;
+	r->y1 -= dh >> 1;
+	r->x2 += (dw + 1) >> 1;
+	r->y2 += (dh + 1) >> 1;
+}
+
+/**
+ * drm_rect_translate - translate the rectangle
+ * @r: rectangle to be tranlated
+ * @dx: horizontal translation
+ * @dy: vertical translation
+ *
+ * Move rectangle @r by @dx in the horizontal direction,
+ * and by @dy in the vertical direction.
+ */
+static inline void drm_rect_translate(struct drm_rect *r, int dx, int dy)
+{
+	r->x1 += dx;
+	r->y1 += dy;
+	r->x2 += dx;
+	r->y2 += dy;
+}
+
+/**
+ * drm_rect_downscale - downscale a rectangle
+ * @r: rectangle to be downscaled
+ * @horz: horizontal downscale factor
+ * @vert: vertical downscale factor
+ *
+ * Divide the coordinates of rectangle @r by @horz and @vert.
+ */
+static inline void drm_rect_downscale(struct drm_rect *r, int horz, int vert)
+{
+	r->x1 /= horz;
+	r->y1 /= vert;
+	r->x2 /= horz;
+	r->y2 /= vert;
+}
+
+/**
+ * drm_rect_width - determine the rectangle width
+ * @r: rectangle whose width is returned
+ *
+ * RETURNS:
+ * The width of the rectangle.
+ */
+static inline int drm_rect_width(const struct drm_rect *r)
+{
+	return r->x2 - r->x1;
+}
+
+/**
+ * drm_rect_height - determine the rectangle height
+ * @r: rectangle whose height is returned
+ *
+ * RETURNS:
+ * The height of the rectangle.
+ */
+static inline int drm_rect_height(const struct drm_rect *r)
+{
+	return r->y2 - r->y1;
+}
+
+/**
+ * drm_rect_visible - determine if the the rectangle is visible
+ * @r: rectangle whose visibility is returned
+ *
+ * RETURNS:
+ * %true if the rectangle is visible, %false otherwise.
+ */
+static inline bool drm_rect_visible(const struct drm_rect *r)
+{
+	return drm_rect_width(r) > 0 && drm_rect_height(r) > 0;
+}
+
+bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
+bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
+			  const struct drm_rect *clip,
+			  int hscale, int vscale);
+
+#endif
-- 
1.8.1.5

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Re: [PATCH v4] drm: Add struct drm_rect and assorted utility functions

[Laurent Pinchart]

Hi Ville,

Thanks for the patch.

On Friday 05 April 2013 16:19:36 ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> struct drm_rect represents a simple rectangle. The utility
> functions are there to help driver writers.
> 
> v2: Moved the region stuff into its own file, made the smaller funcs
>     static inline, used 64bit maths in the scaled clipping function to
>     avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
> v3: Renamed drm_region to drm_rect, drm_region_clip to
>     drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
> v4: Renamed some function parameters, improve kernel-doc comments a bit,
>     and actually generate documentation for drm_rect.[ch].
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  Documentation/DocBook/drm.tmpl |   2 +
>  drivers/gpu/drm/Makefile       |   3 +-
>  drivers/gpu/drm/drm_rect.c     |  96 ++++++++++++++++++++++++++++++
>  include/drm/drm_rect.h         | 132 ++++++++++++++++++++++++++++++++++++++
>  4 files changed, 232 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/drm_rect.c
>  create mode 100644 include/drm/drm_rect.h

[snip]

> diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> new file mode 100644
> index 0000000..a9861bd
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_rect.c

[snip]

> +/**
> + * drm_rect_clip_scaled - perform a scaled clip operation
> + * @src: source window rectangle
> + * @dst: destination window rectangle
> + * @clip: clip rectangle
> + * @hscale: horizontal scaling factor
> + * @vscale: vertical scaling factor
> + *
> + * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
> + * same amounts multiplied by @hscale and @vscale.
> + *
> + * RETUTRNS:

s/RETUTRNS/RETURNS/

> + * %true if rectangle @dst is still visible after being clipped,
> + * %false otherwise
> + */

Otherwise,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Regards,

Laurent Pinchart

Re: [PATCH v4] drm: Add struct drm_rect and assorted utility functions

[Ville Syrjälä]

On Sat, Apr 06, 2013 at 02:00:31AM +0200, Laurent Pinchart wrote:
> Hi Ville,
> 
> Thanks for the patch.
> 
> On Friday 05 April 2013 16:19:36 ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > struct drm_rect represents a simple rectangle. The utility
> > functions are there to help driver writers.
> > 
> > v2: Moved the region stuff into its own file, made the smaller funcs
> >     static inline, used 64bit maths in the scaled clipping function to
> >     avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
> > v3: Renamed drm_region to drm_rect, drm_region_clip to
> >     drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
> > v4: Renamed some function parameters, improve kernel-doc comments a bit,
> >     and actually generate documentation for drm_rect.[ch].
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  Documentation/DocBook/drm.tmpl |   2 +
> >  drivers/gpu/drm/Makefile       |   3 +-
> >  drivers/gpu/drm/drm_rect.c     |  96 ++++++++++++++++++++++++++++++
> >  include/drm/drm_rect.h         | 132 ++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 232 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/gpu/drm/drm_rect.c
> >  create mode 100644 include/drm/drm_rect.h
> 
> [snip]
> 
> > diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> > new file mode 100644
> > index 0000000..a9861bd
> > --- /dev/null
> > +++ b/drivers/gpu/drm/drm_rect.c
> 
> [snip]
> 
> > +/**
> > + * drm_rect_clip_scaled - perform a scaled clip operation
> > + * @src: source window rectangle
> > + * @dst: destination window rectangle
> > + * @clip: clip rectangle
> > + * @hscale: horizontal scaling factor
> > + * @vscale: vertical scaling factor
> > + *
> > + * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
> > + * same amounts multiplied by @hscale and @vscale.
> > + *
> > + * RETUTRNS:
> 
> s/RETUTRNS/RETURNS/

Fixed.

> 
> > + * %true if rectangle @dst is still visible after being clipped,
> > + * %false otherwise
> > + */
> 
> Otherwise,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Thank you very much.

-- 
Ville Syrjälä
Intel OTC