Move some Canvas code to Texture, devirtualize Texture::draw.

src/common/pixelformat.cpp

@@ -137,6 +137,20 @@ bool isPixelFormatStencil(PixelFormat format)
 	return format == PIXELFORMAT_STENCIL8 || format == PIXELFORMAT_DEPTH24_UNORM_STENCIL8 || format == PIXELFORMAT_DEPTH32_FLOAT_STENCIL8;
 }
 
+PixelFormat getSRGBPixelFormat(PixelFormat format)
+{
+	if (format == PIXELFORMAT_RGBA8_UNORM)
+		return PIXELFORMAT_sRGBA8_UNORM;
+	return format;
+}
+
+PixelFormat getLinearPixelFormat(PixelFormat format)
+{
+	if (format == PIXELFORMAT_sRGBA8_UNORM)
+		return PIXELFORMAT_RGBA8_UNORM;
+	return format;
+}
+
 size_t getPixelFormatSize(PixelFormat format)
 {
 	switch (format)

src/common/pixelformat.h

@@ -132,6 +132,16 @@ bool isPixelFormatDepth(PixelFormat format);
  **/
 bool isPixelFormatStencil(PixelFormat format);
 
+/**
+ * Gets the sRGB version of a linear pixel format, if applicable.
+ **/
+PixelFormat getSRGBPixelFormat(PixelFormat format);
+
+/**
+ * Gets the linear version of a sRGB pixel format, if applicable.
+ **/
+PixelFormat getLinearPixelFormat(PixelFormat format);
+
 /**
  * Gets the size in bytes of the specified pixel format.
  * NOTE: Currently returns 0 for compressed formats.