Fix drawTiledPixmap for NPOT pixmaps on OpenGL ES 2.0

OpenGL ES does not support GL_REPEAT wrap modes for NPOT textures. So
instead, we emulate GL_REPEAT by only taking the fractional part of the
texture coords in the fragment shader.

Task-number: 260982
Reviewed-by: Samuel

1 files changed, 12 insertions, 0 deletions

diff --git a/src/opengl/gl2paintengineex/qglengineshadersource_p.h b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
index acd4461..6bcf010 100644
--- a/src/opengl/gl2paintengineex/qglengineshadersource_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
@@ -260,12 +260,24 @@ static const char* const qglslPositionWithTextureBrushVertexShader = "\
 static const char* const qglslAffinePositionWithTextureBrushVertexShader
                  = qglslPositionWithTextureBrushVertexShader;
 
+#if defined(QT_OPENGL_ES_2)
+// OpenGL ES does not support GL_REPEAT wrap modes for NPOT textures. So instead,
+// we emulate GL_REPEAT by only taking the fractional part of the texture coords.
+// TODO: Special case POT textures which don't need this emulation
+static const char* const qglslTextureBrushSrcFragmentShader = "\
+    varying highp   vec2      brushTextureCoords; \
+    uniform lowp    sampler2D brushTexture; \
+    lowp vec4 srcPixel() { \
+        return texture2D(brushTexture, fract(brushTextureCoords)); \
+    }";
+#else
 static const char* const qglslTextureBrushSrcFragmentShader = "\
     varying highp   vec2      brushTextureCoords; \
     uniform lowp    sampler2D brushTexture; \
     lowp vec4 srcPixel() { \
         return texture2D(brushTexture, brushTextureCoords); \
     }";
+#endif
 
 static const char* const qglslTextureBrushSrcWithPatternFragmentShader = "\
     varying highp   vec2      brushTextureCoords; \