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* [PATCH] drm/vkms: Use alpha value to blend values.
@ 2019-09-01  8:56 Sidong Yang
  0 siblings, 0 replies; 8+ messages in thread
From: Sidong Yang @ 2019-09-01  8:56 UTC (permalink / raw)
  To: Rodrigo Siqueira, Haneen Mohammed, Daniel Vetter, David Airlie
  Cc: dri-devel, linux-kernel

Use alpha value to blend source value and destination value Instead of
just overwrite with source value.

Signed-off-by: Sidong Yang <realwakka@gmail.com>
---
 drivers/gpu/drm/vkms/vkms_composer.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index d5585695c64d..b776185e5cb5 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -75,6 +75,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 	int y_limit = y_src + h_dst;
 	int x_limit = x_src + w_dst;
 
+	u8 *src, *dst;
+	u32 alpha, inv_alpha;
+
 	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
 		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
 			offset_dst = dest_composer->offset
@@ -84,8 +87,14 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 				     + (i * src_composer->pitch)
 				     + (j * src_composer->cpp);
 
-			memcpy(vaddr_dst + offset_dst,
-			       vaddr_src + offset_src, sizeof(u32));
+			src = vaddr_src + offset_src;
+			dst = vaddr_dst + offset_dst;
+			alpha = src[3] + 1;
+			inv_alpha = 256 - src[3];
+			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
+			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
+			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
+			dst[3] = 0xff;
 		}
 		i_dst++;
 	}
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* Re: [PATCH] drm/vkms: Use alpha value to blend values.
  2020-08-25  3:15 ` Rodrigo Siqueira
@ 2020-08-25 12:35   ` Sidong Yang
  0 siblings, 0 replies; 8+ messages in thread
From: Sidong Yang @ 2020-08-25 12:35 UTC (permalink / raw)
  To: Rodrigo Siqueira
  Cc: Haneen Mohammed, Daniel Vetter, David Airlie, Rodrigo Siqueira,
	dri-devel, linux-kernel, kernel-usp

On Mon, Aug 24, 2020 at 11:15:01PM -0400, Rodrigo Siqueira wrote:
> Hi Sidong,
> 
> Thanks a lot for your patch and effort to improve VKMS.
> 
> On 08/18, Sidong Yang wrote:
> > I wrote this patch for TODO list in vkms documentation.
> > 
> > Use alpha value to blend source value and destination value Instead of
> > just overwrite with source value.
> > 
> > Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
> > Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
> > 
> > Signed-off-by: Sidong Yang <realwakka@gmail.com>
> > ---
> >  drivers/gpu/drm/vkms/vkms_composer.c | 14 ++++++++++++--
> >  1 file changed, 12 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> > index 4f3b07a32b60..e3230e2a99af 100644
> > --- a/drivers/gpu/drm/vkms/vkms_composer.c
> > +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> > @@ -77,6 +77,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
> >  
> >  	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
> >  		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
> > +			u8 *src, *dst;
> > +			u32 alpha, inv_alpha;
> > +
> >  			offset_dst = dest_composer->offset
> >  				     + (i_dst * dest_composer->pitch)
> >  				     + (j_dst++ * dest_composer->cpp);
> > @@ -84,8 +87,15 @@ static void blend(void *vaddr_dst, void *vaddr_src,
> >  				     + (i * src_composer->pitch)
> >  				     + (j * src_composer->cpp);
> >  
> > -			memcpy(vaddr_dst + offset_dst,
> > -			       vaddr_src + offset_src, sizeof(u32));
> > +			src = vaddr_src + offset_src;
> > +			dst = vaddr_dst + offset_dst;
> > +			alpha = src[3] + 1;
> > +			inv_alpha = 256 - src[3];
> > +			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
> > +			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
> > +			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
> 

Hi, Rodrigo!

> Did you test your change with IGT? Maybe I missed something but looks
> like that you're applying the alpha value but the value that we get is
> already pre-multiplied.
> 
> Btw, It looks like that you and Melissa are working in the same feature,
> maybe you two could try to sync for avoiding overlapping.

Thanks for review.
Yes, this patch should be dropped and I should watch Melissa's patch.

> 
> Finally, do you have plans to send your fix for
> vkms_get_vblank_timestamp() function? That patch was really good and
> removes a lot of warning generated during the IGT test.

Okay, I'll work for improve vkms_get_vblank_timestamp().
Thank you so much.

Sincerely,
-Sidong

> 
> Best Regards
> 
> > +			dst[3] = 0xff;
> > +
> >  		}
> >  		i_dst++;
> >  	}
> > -- 
> > 2.17.1
> > 
> 
> -- 
> Rodrigo Siqueira
> https://siqueira.tech



^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] drm/vkms: Use alpha value to blend values.
  2020-08-18 16:02 Sidong Yang
@ 2020-08-25  3:15 ` Rodrigo Siqueira
  2020-08-25 12:35   ` Sidong Yang
  0 siblings, 1 reply; 8+ messages in thread
From: Rodrigo Siqueira @ 2020-08-25  3:15 UTC (permalink / raw)
  To: Sidong Yang
  Cc: Haneen Mohammed, Daniel Vetter, David Airlie, Rodrigo Siqueira,
	dri-devel, linux-kernel, kernel-usp

[-- Attachment #1: Type: text/plain, Size: 2367 bytes --]

Hi Sidong,

Thanks a lot for your patch and effort to improve VKMS.

On 08/18, Sidong Yang wrote:
> I wrote this patch for TODO list in vkms documentation.
> 
> Use alpha value to blend source value and destination value Instead of
> just overwrite with source value.
> 
> Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
> Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
> 
> Signed-off-by: Sidong Yang <realwakka@gmail.com>
> ---
>  drivers/gpu/drm/vkms/vkms_composer.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> index 4f3b07a32b60..e3230e2a99af 100644
> --- a/drivers/gpu/drm/vkms/vkms_composer.c
> +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> @@ -77,6 +77,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
>  
>  	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
>  		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
> +			u8 *src, *dst;
> +			u32 alpha, inv_alpha;
> +
>  			offset_dst = dest_composer->offset
>  				     + (i_dst * dest_composer->pitch)
>  				     + (j_dst++ * dest_composer->cpp);
> @@ -84,8 +87,15 @@ static void blend(void *vaddr_dst, void *vaddr_src,
>  				     + (i * src_composer->pitch)
>  				     + (j * src_composer->cpp);
>  
> -			memcpy(vaddr_dst + offset_dst,
> -			       vaddr_src + offset_src, sizeof(u32));
> +			src = vaddr_src + offset_src;
> +			dst = vaddr_dst + offset_dst;
> +			alpha = src[3] + 1;
> +			inv_alpha = 256 - src[3];
> +			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
> +			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
> +			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;

Did you test your change with IGT? Maybe I missed something but looks
like that you're applying the alpha value but the value that we get is
already pre-multiplied.

Btw, It looks like that you and Melissa are working in the same feature,
maybe you two could try to sync for avoiding overlapping.

Finally, do you have plans to send your fix for
vkms_get_vblank_timestamp() function? That patch was really good and
removes a lot of warning generated during the IGT test.

Best Regards

> +			dst[3] = 0xff;
> +
>  		}
>  		i_dst++;
>  	}
> -- 
> 2.17.1
> 

-- 
Rodrigo Siqueira
https://siqueira.tech

[-- Attachment #2: signature.asc --]
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^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH] drm/vkms: Use alpha value to blend values.
@ 2020-08-18 16:02 Sidong Yang
  2020-08-25  3:15 ` Rodrigo Siqueira
  0 siblings, 1 reply; 8+ messages in thread
From: Sidong Yang @ 2020-08-18 16:02 UTC (permalink / raw)
  To: Rodrigo Siqueira, Haneen Mohammed, Daniel Vetter, David Airlie,
	Rodrigo Siqueira
  Cc: Sidong Yang, dri-devel, linux-kernel, kernel-usp

I wrote this patch for TODO list in vkms documentation.

Use alpha value to blend source value and destination value Instead of
just overwrite with source value.

Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>

Signed-off-by: Sidong Yang <realwakka@gmail.com>
---
 drivers/gpu/drm/vkms/vkms_composer.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index 4f3b07a32b60..e3230e2a99af 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -77,6 +77,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 
 	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
 		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
+			u8 *src, *dst;
+			u32 alpha, inv_alpha;
+
 			offset_dst = dest_composer->offset
 				     + (i_dst * dest_composer->pitch)
 				     + (j_dst++ * dest_composer->cpp);
@@ -84,8 +87,15 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 				     + (i * src_composer->pitch)
 				     + (j * src_composer->cpp);
 
-			memcpy(vaddr_dst + offset_dst,
-			       vaddr_src + offset_src, sizeof(u32));
+			src = vaddr_src + offset_src;
+			dst = vaddr_dst + offset_dst;
+			alpha = src[3] + 1;
+			inv_alpha = 256 - src[3];
+			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
+			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
+			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
+			dst[3] = 0xff;
+
 		}
 		i_dst++;
 	}
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* Re: [PATCH] drm/vkms: Use alpha value to blend values.
  2019-09-04  7:27   ` Sidong Yang
@ 2019-09-04 15:48     ` Ville Syrjälä
  0 siblings, 0 replies; 8+ messages in thread
From: Ville Syrjälä @ 2019-09-04 15:48 UTC (permalink / raw)
  To: Sidong Yang
  Cc: Rodrigo Siqueira, David Airlie, Haneen Mohammed, dri-devel, linux-kernel

On Wed, Sep 04, 2019 at 08:27:07AM +0100, Sidong Yang wrote:
> On Mon, Sep 02, 2019 at 03:28:58PM +0300, Ville Syrjälä wrote:
> > On Sat, Aug 31, 2019 at 06:25:46PM +0100, Sidong Yang wrote:
> > > Use alpha value to blend source value and destination value Instead of
> > > just overwrite with source value.
> > > 
> > > Signed-off-by: Sidong Yang <realwakka@gmail.com>
> > > ---
> > >  drivers/gpu/drm/vkms/vkms_composer.c | 13 +++++++++++--
> > >  1 file changed, 11 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> > > index d5585695c64d..b776185e5cb5 100644
> > > --- a/drivers/gpu/drm/vkms/vkms_composer.c
> > > +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> > > @@ -75,6 +75,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
> > >  	int y_limit = y_src + h_dst;
> > >  	int x_limit = x_src + w_dst;
> > >  
> > > +	u8 *src, *dst;
> > > +	u32 alpha, inv_alpha;
> > 
> > These could all live in a tighter scope.
> 
> Hi, Ville.
> 
> Thank you for reviewing my patch.
> I think that's good idea and I'll do that in next version.
> I found some patch in mailing list that is similar with this patch.
> So should I drop this patch and find other thing?

Probably best if you discuss that with whoever sent that other patch.

> 
> Sidong.
> 
> > 
> > Apart from that lgtm
> > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > > +
> > >  	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
> > >  		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
> > >  			offset_dst = dest_composer->offset
> > > @@ -84,8 +87,14 @@ static void blend(void *vaddr_dst, void *vaddr_src,
> > >  				     + (i * src_composer->pitch)
> > >  				     + (j * src_composer->cpp);
> > >  
> > > -			memcpy(vaddr_dst + offset_dst,
> > > -			       vaddr_src + offset_src, sizeof(u32));
> > > +			src = vaddr_src + offset_src;
> > > +			dst = vaddr_dst + offset_dst;
> > > +			alpha = src[3] + 1;
> > > +			inv_alpha = 256 - src[3];
> > > +			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
> > > +			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
> > > +			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
> > > +			dst[3] = 0xff;
> > >  		}
> > >  		i_dst++;
> > >  	}
> > > -- 
> > > 2.20.1
> > > 
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > 
> > -- 
> > Ville Syrjälä
> > Intel

-- 
Ville Syrjälä
Intel

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] drm/vkms: Use alpha value to blend values.
  2019-09-02 12:28 ` Ville Syrjälä
@ 2019-09-04  7:27   ` Sidong Yang
  2019-09-04 15:48     ` Ville Syrjälä
  0 siblings, 1 reply; 8+ messages in thread
From: Sidong Yang @ 2019-09-04  7:27 UTC (permalink / raw)
  To: Ville Syrjälä
  Cc: Rodrigo Siqueira, David Airlie, Haneen Mohammed, dri-devel, linux-kernel

On Mon, Sep 02, 2019 at 03:28:58PM +0300, Ville Syrjälä wrote:
> On Sat, Aug 31, 2019 at 06:25:46PM +0100, Sidong Yang wrote:
> > Use alpha value to blend source value and destination value Instead of
> > just overwrite with source value.
> > 
> > Signed-off-by: Sidong Yang <realwakka@gmail.com>
> > ---
> >  drivers/gpu/drm/vkms/vkms_composer.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> > index d5585695c64d..b776185e5cb5 100644
> > --- a/drivers/gpu/drm/vkms/vkms_composer.c
> > +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> > @@ -75,6 +75,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
> >  	int y_limit = y_src + h_dst;
> >  	int x_limit = x_src + w_dst;
> >  
> > +	u8 *src, *dst;
> > +	u32 alpha, inv_alpha;
> 
> These could all live in a tighter scope.

Hi, Ville.

Thank you for reviewing my patch.
I think that's good idea and I'll do that in next version.
I found some patch in mailing list that is similar with this patch.
So should I drop this patch and find other thing?

Sidong.

> 
> Apart from that lgtm
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> > +
> >  	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
> >  		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
> >  			offset_dst = dest_composer->offset
> > @@ -84,8 +87,14 @@ static void blend(void *vaddr_dst, void *vaddr_src,
> >  				     + (i * src_composer->pitch)
> >  				     + (j * src_composer->cpp);
> >  
> > -			memcpy(vaddr_dst + offset_dst,
> > -			       vaddr_src + offset_src, sizeof(u32));
> > +			src = vaddr_src + offset_src;
> > +			dst = vaddr_dst + offset_dst;
> > +			alpha = src[3] + 1;
> > +			inv_alpha = 256 - src[3];
> > +			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
> > +			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
> > +			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
> > +			dst[3] = 0xff;
> >  		}
> >  		i_dst++;
> >  	}
> > -- 
> > 2.20.1
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Ville Syrjälä
> Intel

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] drm/vkms: Use alpha value to blend values.
  2019-08-31 17:25 Sidong Yang
@ 2019-09-02 12:28 ` Ville Syrjälä
  2019-09-04  7:27   ` Sidong Yang
  0 siblings, 1 reply; 8+ messages in thread
From: Ville Syrjälä @ 2019-09-02 12:28 UTC (permalink / raw)
  To: Sidong Yang
  Cc: Rodrigo Siqueira, David Airlie, Haneen Mohammed, dri-devel, linux-kernel

On Sat, Aug 31, 2019 at 06:25:46PM +0100, Sidong Yang wrote:
> Use alpha value to blend source value and destination value Instead of
> just overwrite with source value.
> 
> Signed-off-by: Sidong Yang <realwakka@gmail.com>
> ---
>  drivers/gpu/drm/vkms/vkms_composer.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> index d5585695c64d..b776185e5cb5 100644
> --- a/drivers/gpu/drm/vkms/vkms_composer.c
> +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> @@ -75,6 +75,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
>  	int y_limit = y_src + h_dst;
>  	int x_limit = x_src + w_dst;
>  
> +	u8 *src, *dst;
> +	u32 alpha, inv_alpha;

These could all live in a tighter scope.

Apart from that lgtm
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> +
>  	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
>  		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
>  			offset_dst = dest_composer->offset
> @@ -84,8 +87,14 @@ static void blend(void *vaddr_dst, void *vaddr_src,
>  				     + (i * src_composer->pitch)
>  				     + (j * src_composer->cpp);
>  
> -			memcpy(vaddr_dst + offset_dst,
> -			       vaddr_src + offset_src, sizeof(u32));
> +			src = vaddr_src + offset_src;
> +			dst = vaddr_dst + offset_dst;
> +			alpha = src[3] + 1;
> +			inv_alpha = 256 - src[3];
> +			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
> +			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
> +			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
> +			dst[3] = 0xff;
>  		}
>  		i_dst++;
>  	}
> -- 
> 2.20.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Ville Syrjälä
Intel

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH] drm/vkms: Use alpha value to blend values.
@ 2019-08-31 17:25 Sidong Yang
  2019-09-02 12:28 ` Ville Syrjälä
  0 siblings, 1 reply; 8+ messages in thread
From: Sidong Yang @ 2019-08-31 17:25 UTC (permalink / raw)
  To: Rodrigo Siqueira
  Cc: Haneen Mohammed, Daniel Vetter, David Airlie, dri-devel, linux-kernel

Use alpha value to blend source value and destination value Instead of
just overwrite with source value.

Signed-off-by: Sidong Yang <realwakka@gmail.com>
---
 drivers/gpu/drm/vkms/vkms_composer.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index d5585695c64d..b776185e5cb5 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -75,6 +75,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 	int y_limit = y_src + h_dst;
 	int x_limit = x_src + w_dst;
 
+	u8 *src, *dst;
+	u32 alpha, inv_alpha;
+
 	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
 		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
 			offset_dst = dest_composer->offset
@@ -84,8 +87,14 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 				     + (i * src_composer->pitch)
 				     + (j * src_composer->cpp);
 
-			memcpy(vaddr_dst + offset_dst,
-			       vaddr_src + offset_src, sizeof(u32));
+			src = vaddr_src + offset_src;
+			dst = vaddr_dst + offset_dst;
+			alpha = src[3] + 1;
+			inv_alpha = 256 - src[3];
+			dst[0] = (alpha * src[0] + inv_alpha * dst[0]) >> 8;
+			dst[1] = (alpha * src[1] + inv_alpha * dst[1]) >> 8;
+			dst[2] = (alpha * src[2] + inv_alpha * dst[2]) >> 8;
+			dst[3] = 0xff;
 		}
 		i_dst++;
 	}
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-08-25 12:36 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-01  8:56 [PATCH] drm/vkms: Use alpha value to blend values Sidong Yang
  -- strict thread matches above, loose matches on Subject: below --
2020-08-18 16:02 Sidong Yang
2020-08-25  3:15 ` Rodrigo Siqueira
2020-08-25 12:35   ` Sidong Yang
2019-08-31 17:25 Sidong Yang
2019-09-02 12:28 ` Ville Syrjälä
2019-09-04  7:27   ` Sidong Yang
2019-09-04 15:48     ` Ville Syrjälä

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