[TextureMapper] min(genIType) isn't supported for GLSL ES < 3.0

https://bugs.webkit.org/show_bug.cgi?id=218164

Reviewed by Don Olmstead.

Nothing is drawn in AC mode of WinCairo port since r268923.
r268923 added a shader code of using min of int type which is
supported since GLSL ES 3.0.

* platform/graphics/texmap/TextureMapperShaderProgram.cpp: Added fragmentTemplateES to define int type of min.
(WebCore::TextureMapperShaderProgram::create):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@268992 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Author: [email protected]

Source/WebCore/ChangeLog

@@ -1,3 +1,17 @@
+2020-10-26  Fujii Hironori  <[email protected]>
+
+        [TextureMapper] min(genIType) isn't supported for GLSL ES < 3.0
+        https://bugs.webkit.org/show_bug.cgi?id=218164
+
+        Reviewed by Don Olmstead.
+
+        Nothing is drawn in AC mode of WinCairo port since r268923.
+        r268923 added a shader code of using min of int type which is
+        supported since GLSL ES 3.0.
+
+        * platform/graphics/texmap/TextureMapperShaderProgram.cpp: Added fragmentTemplateES to define int type of min.
+        (WebCore::TextureMapperShaderProgram::create):
+
 2020-10-26  Sam Weinig  <[email protected]>
 
         JSC special function forward declarations (e.g. JSC_DECLARE_HOST_FUNCTION) that are internal to a cpp file should be declared with static to avoid external linkage

Source/WebCore/platform/graphics/texmap/TextureMapperShaderProgram.cpp

@@ -225,6 +225,17 @@ static const char* fragmentTemplateGE320Vars =
         in vec2 v_transformedTexCoord;
         in vec4 v_nonProjectedPosition;
     );
+#else
+// min(genIType) isn't supported for GLSL ES < 3.0.
+static const char* fragmentTemplateES =
+    STRINGIFY(
+        int min(int x, int y)
+        {
+            if (x < y)
+                return x;
+            return y;
+        }
+    );
 #endif
 
 static const char* fragmentTemplateCommon =
@@ -576,6 +587,7 @@ Ref<TextureMapperShaderProgram> TextureMapperShaderProgram::create(TextureMapper
     // Append the appropriate input/output variable definitions.
 #if USE(OPENGL_ES)
     fragmentShaderBuilder.append(fragmentTemplateLT320Vars);
+    fragmentShaderBuilder.append(fragmentTemplateES);
 #else
     if (glVersion >= 320)
         fragmentShaderBuilder.append(fragmentTemplateGE320Vars);