Use the alpha value to blend vaddr_src with vaddr_dst instead
of overwriting it in blend().
Signed-off-by: Mamta Shukla <mamtashukla...@gmail.com>
---
changes in v2:
-Use macro to avoid code duplication
-Add spaces around '/' and '-'
-Remove spaces at the end of the line
drivers/gpu/drm/vkms/vkms_crc.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c
index 9d9e8146db90..dc6cb4c2cced 100644
--- a/drivers/gpu/drm/vkms/vkms_crc.c
+++ b/drivers/gpu/drm/vkms/vkms_crc.c
@@ -5,6 +5,8 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
+#define BITSHIFT(val,i) (u8)((*(u32 *)(val)) >> i & 0xff)
+
/**
* compute_crc - Compute CRC value on output frame
*
@@ -71,6 +73,9 @@ static void blend(void *vaddr_dst, void *vaddr_src,
int y_limit = y_src + h_dst;
int x_limit = x_src + w_dst;
+ u8 alpha, r_src, r_dst, g_src, g_dst, b_src, b_dst;
+ u8 r_alpha, g_alpha, b_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 = crc_dst->offset
@@ -79,9 +84,25 @@ static void blend(void *vaddr_dst, void *vaddr_src,
offset_src = crc_src->offset
+ (i * crc_src->pitch)
+ (j * crc_src->cpp);
+
+ /*Currently handles alpha values for fully opaque or
fully transparent*/
+ alpha = (u8)((*(u32 *)vaddr_src + offset_src) >> 24);
+ alpha = alpha / 255;
+ r_src = BITSHIFT(vaddr_src + offset_src, 16);
+ g_src = BITSHIFT(vaddr_src + offset_src, 8);
+ b_src = BITSHIFT(vaddr_src + offset_src, 0);
+ r_dst = BITSHIFT(vaddr_dst + offset_dst, 16);
+ g_dst = BITSHIFT(vaddr_dst + offset_dst, 8);
+ b_dst = BITSHIFT(vaddr_dst + offset_dst, 0);
+
+ /*Pre-multiplied alpha for blending */
+ r_alpha = (r_src) + (r_dst * (1 - alpha));
+ g_alpha = (g_src) + (g_dst * (1 - alpha));
+ b_alpha = (b_src) + (b_dst * (1 - alpha));
+ memset(vaddr_dst + offset_dst, b_alpha, sizeof(u8));
+ memset(vaddr_dst + offset_dst + 1, g_alpha, sizeof(u8));
+ memset(vaddr_dst + offset_dst + 2, r_alpha, sizeof(u8));
- memcpy(vaddr_dst + offset_dst,
- vaddr_src + offset_src, sizeof(u32));
}
i_dst++;
}
--
2.17.1
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