Tweak art_pdf_composite_pixel_alpha_8_inline.

Normal blending allows us to not only skip the art_blend_pixel_8_inline
call, but also to simplify the calculations.

1 files changed, 25 insertions, 15 deletions

diff --git a/base/gxblend.c b/base/gxblend.c
index 59f990b1a..1adad4b4e 100644
--- a/base/gxblend.c
+++ b/base/gxblend.c
@@ -989,21 +989,31 @@ art_pdf_composite_pixel_alpha_8_inline(byte *dst, byte *src, int n_chan,
     src_scale = ((a_s << 16) + (a_r >> 1)) / a_r;
 
     if (first_spot != 0) {
-        /* Do compositing with blending */
-        byte blend[ART_MAX_CHAN];
-
-        art_blend_pixel_8_inline(blend, dst, src, first_spot, blend_mode, pblend_procs, p14dev);
-        for (i = 0; i < first_spot; i++) {
-            int c_bl;		/* Result of blend function */
-            int c_mix;		/* Blend result mixed with source color */
-
-            c_s = src[i];
-            c_b = dst[i];
-            c_bl = blend[i];
-            tmp = a_b * (c_bl - ((int)c_s)) + 0x80;
-            c_mix = c_s + (((tmp >> 8) + tmp) >> 8);
-            tmp = (c_b << 16) + src_scale * (c_mix - c_b) + 0x8000;
-            dst[i] = tmp >> 16;
+        if (blend_mode == BLEND_MODE_Normal)
+        {
+            for (i = 0; i < first_spot; i++) {
+                c_s = src[i];
+                c_b = dst[i];
+                tmp = (c_b << 16) + src_scale * (c_s - c_b) + 0x8000;
+                dst[i] = tmp >> 16;
+            }
+        } else {
+            /* Do compositing with blending */
+            byte blend[ART_MAX_CHAN];
+
+            art_blend_pixel_8_inline(blend, dst, src, first_spot, blend_mode, pblend_procs, p14dev);
+            for (i = 0; i < first_spot; i++) {
+                int c_bl;		/* Result of blend function */
+                int c_mix;		/* Blend result mixed with source color */
+
+                c_s = src[i];
+                c_b = dst[i];
+                c_bl = blend[i];
+                tmp = a_b * (c_bl - ((int)c_s)) + 0x80;
+                c_mix = c_s + (((tmp >> 8) + tmp) >> 8);
+                tmp = (c_b << 16) + src_scale * (c_mix - c_b) + 0x8000;
+                dst[i] = tmp >> 16;
+            }
         }
     }
     dst[n_chan] = a_r;