const std::string TEXTURE_UNIFORM_NAME = "sTexture";
const std::string ATLAS_RECT_UNIFORM_NAME = "uAtlasRect";
const std::string PIXEL_AREA_UNIFORM_NAME = "pixelArea";
+
+// Set this uniform to 1.0 for conventional alpha blending; if pre-multiplied alpha blending, set this uniform to 0.0
+const std::string ALPHA_BLENDING_UNIFORM_NAME = "uAlphaBlending";
+
const Vector4 FULL_TEXTURE_RECT(0.f, 0.f, 1.f, 1.f);
const char* VERTEX_SHADER = DALI_COMPOSE_SHADER(
varying mediump vec2 vTexCoord;\n
uniform sampler2D sTexture;\n
uniform lowp vec4 uColor;\n
+ uniform lowp float uAlphaBlending; // Set to 1.0 for conventional alpha blending; if pre-multiplied alpha blending, set to 0.0
\n
void main()\n
{\n
- gl_FragColor = texture2D( sTexture, vTexCoord ) * uColor;\n
+ gl_FragColor = texture2D( sTexture, vTexCoord ) * vec4( uColor.rgb*max( uAlphaBlending, uColor.a ), uColor.a );\n
}\n
);
mAtlasManager( atlasManager ),
mDesiredSize(),
mFittingMode( FittingMode::DEFAULT ),
- mSamplingMode( SamplingMode::DEFAULT )
+ mSamplingMode( SamplingMode::DEFAULT ),
+ mIsAlphaPreMultiplied( false )
{
}
{
shader.RegisterProperty( ATLAS_RECT_UNIFORM_NAME, FULL_TEXTURE_RECT );
shader.RegisterProperty( PIXEL_AREA_UNIFORM_NAME, FULL_TEXTURE_RECT );
+ shader.RegisterProperty( ALPHA_BLENDING_UNIFORM_NAME, 1.f );
}
}
}
{
InitializeRenderer( mImage );
}
+
+ EnablePreMultipliedAlpha( mIsAlphaPreMultiplied );
}
void ImageRenderer::DoSetOffStage( Actor& actor )
factoryCache.SaveShader( RendererFactoryCache::IMAGE_SHADER, shader );
shader.RegisterProperty( ATLAS_RECT_UNIFORM_NAME, FULL_TEXTURE_RECT );
shader.RegisterProperty( PIXEL_AREA_UNIFORM_NAME, FULL_TEXTURE_RECT );
+ shader.RegisterProperty( ALPHA_BLENDING_UNIFORM_NAME, 1.f );
}
return shader;
}
}
}
+void ImageRenderer::EnablePreMultipliedAlpha( bool preMultipled )
+{
+ mIsAlphaPreMultiplied = preMultipled;
+ if( mImpl->mRenderer )
+ {
+ Material material = mImpl->mRenderer.GetMaterial();
+
+ if( preMultipled )
+ {
+ material.SetBlendFunc( BlendingFactor::ONE, BlendingFactor::ONE_MINUS_SRC_ALPHA,
+ BlendingFactor::ONE, BlendingFactor::ONE );
+ if( !mImpl->mCustomShader || mImpl->mCustomShader->mVertexShader.empty())
+ {
+ material.RegisterProperty( ALPHA_BLENDING_UNIFORM_NAME, 0.f );
+ }
+ }
+ else
+ {
+ // using default blend func
+ material.SetBlendFunc( BlendingFactor::SRC_ALPHA, BlendingFactor::ONE_MINUS_SRC_ALPHA,
+ BlendingFactor::ONE, BlendingFactor::ONE_MINUS_SRC_ALPHA );
+
+ Property::Index index = material.GetPropertyIndex( ALPHA_BLENDING_UNIFORM_NAME );
+ if( index != Property::INVALID_INDEX ) // only set value when the property already exist on the Material
+ {
+ material.SetProperty( index, 1.f );
+ }
+ }
+ }
+}
+
void ImageRenderer::ApplyImageToSampler( const Image& image )
{
if( image )