Refactor the copy validation matrix.

We were enumerating the color buffer formats by sized internal format,
which is simplified and made less fragile by retrieving the base
internal format and implementing the spec's validation tables more
directly.

Change-Id: I46d244b9ed738e927b0cb5fe6d1deebf6f0cbae5
Reviewed-on: https://swiftshader-review.googlesource.com/16988
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>

src/OpenGL/libGLESv2/utilities.cpp

diff --git a/src/OpenGL/libGLESv2/utilities.cpp b/src/OpenGL/libGLESv2/utilities.cpp
index e435be0..4cf8f52 100644
--- a/src/OpenGL/libGLESv2/utilities.cpp
+++ b/src/OpenGL/libGLESv2/utilities.cpp
@@ -612,52 +612,48 @@
 
 	bool ValidateCopyFormats(GLenum textureFormat, GLenum colorbufferFormat)
 	{
-		if(IsCompressed(textureFormat, egl::getClientVersion()))
-		{
-			return error(GL_INVALID_OPERATION, false);
-		}
-
-		GLenum baseFormat = GetBaseInternalFormat(textureFormat);
+		GLenum baseTexureFormat = GetBaseInternalFormat(textureFormat);
+		GLenum baseColorbufferFormat = GetBaseInternalFormat(colorbufferFormat);
 
 		// [OpenGL ES 2.0.24] table 3.9
 		// [OpenGL ES 3.0.5] table 3.16
-		switch(baseFormat)
+		switch(baseTexureFormat)
 		{
 		case GL_ALPHA:
-			if(colorbufferFormat != GL_RGBA4 &&
-			   colorbufferFormat != GL_RGB5_A1 &&
-			   colorbufferFormat != GL_RGBA8 &&
-			   colorbufferFormat != GL_BGRA8_EXT &&
-			   colorbufferFormat != GL_RGBA16F_EXT &&
-			   colorbufferFormat != GL_RGBA32F_EXT)
-			{
-				return error(GL_INVALID_OPERATION, false);
-			}
-			break;
-		case GL_LUMINANCE:
-		case GL_RGB:
-			if(colorbufferFormat != GL_RGB565 &&
-			   colorbufferFormat != GL_RGB8 &&
-			   colorbufferFormat != GL_RGBA4 &&
-			   colorbufferFormat != GL_RGB5_A1 &&
-			   colorbufferFormat != GL_RGBA8 &&
-			   colorbufferFormat != GL_RGB16F_EXT &&
-			   colorbufferFormat != GL_RGB32F_EXT &&
-			   colorbufferFormat != GL_BGRA8_EXT &&
-			   colorbufferFormat != GL_RGBA16F_EXT &&
-			   colorbufferFormat != GL_RGBA32F_EXT)
+			if(baseColorbufferFormat != GL_ALPHA &&
+			   baseColorbufferFormat != GL_RGBA)
 			{
 				return error(GL_INVALID_OPERATION, false);
 			}
 			break;
 		case GL_LUMINANCE_ALPHA:
 		case GL_RGBA:
-			if(colorbufferFormat != GL_RGBA4 &&
-			   colorbufferFormat != GL_RGB5_A1 &&
-			   colorbufferFormat != GL_RGBA8 &&
-			   colorbufferFormat != GL_BGRA8_EXT &&
-			   colorbufferFormat != GL_RGBA16F_EXT &&
-			   colorbufferFormat != GL_RGBA32F_EXT)
+			if(baseColorbufferFormat != GL_RGBA)
+			{
+				return error(GL_INVALID_OPERATION, false);
+			}
+			break;
+		case GL_LUMINANCE:
+		case GL_RED:
+			if(baseColorbufferFormat != GL_RED &&
+			   baseColorbufferFormat != GL_RG &&
+			   baseColorbufferFormat != GL_RGB &&
+			   baseColorbufferFormat != GL_RGBA)
+			{
+				return error(GL_INVALID_OPERATION, false);
+			}
+			break;
+		case GL_RG:
+			if(baseColorbufferFormat != GL_RG &&
+			   baseColorbufferFormat != GL_RGB &&
+			   baseColorbufferFormat != GL_RGBA)
+			{
+				return error(GL_INVALID_OPERATION, false);
+			}
+			break;
+		case GL_RGB:
+			if(baseColorbufferFormat != GL_RGB &&
+			   baseColorbufferFormat != GL_RGBA)
 			{
 				return error(GL_INVALID_OPERATION, false);
 			}
@@ -1278,6 +1274,16 @@
 	{
 		switch(internalformat)
 		{
+		// Unsized internal formats which are valid as the <internalformat> parameter of CopyTexImage.
+		case GL_RGB:
+		case GL_RGBA:
+		case GL_ALPHA:
+		case GL_LUMINANCE:
+		case GL_LUMINANCE_ALPHA:
+		case GL_RED_EXT:           // GL_EXT_texture_rg
+		case GL_RG_EXT:            // GL_EXT_texture_rg
+			return internalformat;
+
 		// [OpenGL ES 3.0 Table 3.13]
 		case GL_R8:       return GL_RED;
 		case GL_R8_SNORM: return GL_RED;