[Bf-blender-cvs] [5424b4821d2] master: Fix T83094: Alternate rows in the Sequencer are green (macOS)

[Yevgeny Makarov]

Commit: 5424b4821d28c4ea42b4f195869de1e1620e6889
Author: Yevgeny Makarov
Date:   Tue Jan 5 14:21:54 2021 -0600
Branches: master
https://developer.blender.org/rB5424b4821d28c4ea42b4f195869de1e1620e6889

Fix T83094: Alternate rows in the Sequencer are green (macOS)

The issue is that `UI_GetThemeColorBlendShade4fv()` creates a color
with alpha, but there is not any background underneath to blend in with.

The solution is just to draw an opaque background first, which also
halves the number of rects to draw. Note that the brighter rows get
very slightly darker after this change.

Differential Revision: https://developer.blender.org/D9947

===================================================================

M	source/blender/editors/space_sequencer/sequencer_draw.c

===================================================================

diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index d6e1a0c833b..f792f75bf96 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1880,6 +1880,10 @@ static void draw_seq_backdrop(View2D *v2d)
   uint pos = GPU_vertformat_attr_add(immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
 
+  /* View backdrop. */
+  immUniformThemeColorShade(TH_BACK, -25);
+  immRectf(pos, v2d->cur.xmin, v2d->cur.ymin, v2d->cur.xmax, v2d->cur.ymax);
+
   /* Darker overlay over the view backdrop. */
   immUniformThemeColorShade(TH_BACK, -20);
   immRectf(pos, v2d->cur.xmin, -1.0, v2d->cur.xmax, 1.0);
@@ -1887,22 +1891,18 @@ static void draw_seq_backdrop(View2D *v2d)
   /* Alternating horizontal stripes. */
   i = max_ii(1, ((int)v2d->cur.ymin) - 1);
 
-  float col_alternating[4];
-  UI_GetThemeColor4fv(TH_ROW_ALTERNATE, col_alternating);
+  GPU_blend(GPU_BLEND_ALPHA);
+  immUniformThemeColor(TH_ROW_ALTERNATE);
 
   while (i < v2d->cur.ymax) {
     if (i & 1) {
-      immUniformThemeColorBlendShade(TH_BACK, TH_ROW_ALTERNATE, col_alternating[3], -25);
-    }
-    else {
-      immUniformThemeColorShade(TH_BACK, -25);
+      immRectf(pos, v2d->cur.xmin, i, v2d->cur.xmax, i + 1);
     }
-
-    immRectf(pos, v2d->cur.xmin, i, v2d->cur.xmax, i + 1);
-
     i++;
   }
 
+  GPU_blend(GPU_BLEND_NONE);
+
   /* Lines separating the horizontal bands. */
   i = max_ii(1, ((int)v2d->cur.ymin) - 1);
   int line_len = (int)v2d->cur.ymax - i + 1;