Added 3-color gradient scraper for detecting symmetrical gradients.

src/utils/SkLua.cpp

Index: src/utils/SkLua.cpp
diff --git a/src/utils/SkLua.cpp b/src/utils/SkLua.cpp
index 66a9c08597188ceaedcc21a105b249d4ab10ffd6..d8af2bf442f4aa10f5506e9fd99df37034f76f5b 100644
--- a/src/utils/SkLua.cpp
+++ b/src/utils/SkLua.cpp
@@ -712,11 +712,21 @@ static int lshader_asAGradient(lua_State* L) {
     if (shader) {
         SkShader::GradientInfo info;
         sk_bzero(&info, sizeof(info));
+
+        SkColor colors[3];  // hacked in for extracting info on 3 color case.
+        SkScalar pos[3];    // can get data for all gradient types by calling asAGradient twice

[reed1, 2013/08/01 16:00:10]

not sure what this comment means. all types? do we need this comment?

[dierk, 2013/08/01 16:07:39]

Done.

+
+        info.fColorCount = 3;
+        info.fColors = &colors[0];
+        info.fColorOffsets = &pos[0];
+        
         SkShader::GradientType t = shader->asAGradient(&info);
+
         if (SkShader::kNone_GradientType != t) {
             lua_newtable(L);
             setfield_string(L, "type", gradtype2string(t));
             setfield_number(L, "colorCount", info.fColorCount);
+            setfield_number(L, "mid", pos[1]);

[reed1, 2013/08/01 16:00:10]

Should we add this field if colorCount != 3 ?

Perhaps a more descriptive field name?

[dierk, 2013/08/01 16:07:39]

Done.

             setfield_string(L, "tile", mode2string(info.fTileMode));
             return 1;
         }