Nikolay Sivov : dwrite: Handle 8bpp gray bitmaps for bitmap target.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 55aedbffa6418c92ad6282ee10b00169149a0d2c
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=55aedbffa6418c92ad6282ee10...

Author: Nikolay Sivov <nsivov(a)codeweavers.com>
Date:   Tue Sep  5 13:35:27 2017 +0300

dwrite: Handle 8bpp gray bitmaps for bitmap target.

Signed-off-by: Nikolay Sivov <nsivov(a)codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>

---

 dlls/dwrite/gdiinterop.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/dlls/dwrite/gdiinterop.c b/dlls/dwrite/gdiinterop.c
index 5425b5c..2e1811b 100644
--- a/dlls/dwrite/gdiinterop.c
+++ b/dlls/dwrite/gdiinterop.c
@@ -256,6 +256,25 @@ static inline DWORD *get_pixel_ptr_32(struct dib_data *dib, int x, int y)
     return (DWORD *)((BYTE*)dib->ptr + y * dib->stride + x * 4);
 }
 
+static inline BYTE blend_color(BYTE dst, BYTE src, BYTE alpha)
+{
+    return (src * alpha + dst * (255 - alpha) + 127) / 255;
+}
+
+static inline DWORD blend_subpixel(BYTE r, BYTE g, BYTE b, DWORD text, const BYTE *alpha)
+{
+    return blend_color(r, text >> 16, alpha[0]) << 16 |
+           blend_color(g, text >> 8,  alpha[1]) << 8  |
+           blend_color(b, text,       alpha[2]);
+}
+
+static inline DWORD blend_pixel(BYTE r, BYTE g, BYTE b, DWORD text, BYTE alpha)
+{
+    return blend_color(r, text >> 16, alpha) << 16 |
+           blend_color(g, text >> 8,  alpha) << 8  |
+           blend_color(b, text,       alpha);
+}
+
 static void blit_8(struct dib_data *dib, const BYTE *src, const RECT *rect, DWORD text_pixel)
 {
     DWORD *dst_ptr = get_pixel_ptr_32(dib, rect->left, rect->top);
@@ -263,8 +282,11 @@ static void blit_8(struct dib_data *dib, const BYTE *src, const RECT *rect, DWOR
 
     for (y = rect->top; y < rect->bottom; y++) {
         for (x = 0; x < src_width; x++) {
-            if (src[x] < DWRITE_ALPHA_MAX) continue;
-            dst_ptr[x] = text_pixel;
+            if (src[x]) continue;
+            if (src[x] == DWRITE_ALPHA_MAX)
+                dst_ptr[x] = text_pixel;
+            else
+                dst_ptr[x] = blend_pixel(dst_ptr[x] >> 16, dst_ptr[x] >> 8, dst_ptr[x], text_pixel, src[x]);
         }
 
         src += src_width;
@@ -272,18 +294,6 @@ static void blit_8(struct dib_data *dib, const BYTE *src, const RECT *rect, DWOR
     }
 }
 
-static inline BYTE blend_color(BYTE dst, BYTE src, BYTE alpha)
-{
-    return (src * alpha + dst * (255 - alpha) + 127) / 255;
-}
-
-static inline DWORD blend_subpixel(BYTE r, BYTE g, BYTE b, DWORD text, const BYTE *alpha)
-{
-    return blend_color(r, text >> 16, alpha[0]) << 16 |
-           blend_color(g, text >> 8,  alpha[1]) << 8  |
-           blend_color(b, text,       alpha[2]);
-}
-
 static void blit_subpixel_888(struct dib_data *dib, int dib_width, const BYTE *src,
     const RECT *rect, DWORD text_pixel)
 {