Added some missing bits of support for PVRTC, ATC, and ETC1 textures

Source/core/html/canvas/WebGLRenderingContextBase.cpp

Index: Source/core/html/canvas/WebGLRenderingContextBase.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContextBase.cpp b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
index d9a684713346b45c30412904a0e509eb76b010da..98b3667f40a8ae529b5abc05b0f2496a5a0788f8 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -4825,13 +4825,13 @@ bool WebGLRenderingContextBase::validateCompressedTexFuncData(const char* functi
     case GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG:
     case GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG:
         {
-            bytesRequired = max(width, 8) * max(height, 8) / 2;
+            bytesRequired = (max(width, 8) * max(height, 8) * 4 + 7) / 8;

[Ken Russell (switch to Gerrit), 2014/04/18 01:56:35]

Please submit a pull request updating the extension registry.

         }
         break;
     case GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG:
     case GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG:
         {
-            bytesRequired = max(width, 8) * max(height, 8) / 4;
+            bytesRequired = (max(width, 16) * max(height, 8) * 2 + 7) / 8;

[Ken Russell (switch to Gerrit), 2014/04/18 01:56:35]

Same for this change.

         }
         break;
     default:
@@ -4852,24 +4852,47 @@ bool WebGLRenderingContextBase::validateCompressedTexDimensions(const char* func
     if (!validateTexFuncDimensions(functionName, functionType, target, level, width, height))
         return false;
 
+    bool widthValid = false;
+    bool heightValid = false;
+
     switch (format) {
+    case GC3D_COMPRESSED_ATC_RGB_AMD:
+    case GC3D_COMPRESSED_ATC_RGBA_EXPLICIT_ALPHA_AMD:
+    case GC3D_COMPRESSED_ATC_RGBA_INTERPOLATED_ALPHA_AMD:
     case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
     case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
     case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
     case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: {
         const int kBlockWidth = 4;
         const int kBlockHeight = 4;
-        bool widthValid = (level && width == 1) || (level && width == 2) || !(width % kBlockWidth);
-        bool heightValid = (level && height == 1) || (level && height == 2) || !(height % kBlockHeight);
-        if (!widthValid || !heightValid) {
-            synthesizeGLError(GL_INVALID_OPERATION, functionName, "width or height invalid for level");
-            return false;
-        }
-        return true;
+        widthValid = (level && width == 1) || (level && width == 2) || !(width % kBlockWidth);
+        heightValid = (level && height == 1) || (level && height == 2) || !(height % kBlockHeight);
+        break;
+    }
+    case GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG:
+    case GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG:
+    case GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG:
+    case GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG: {
+        // Must be a power of two
+        widthValid = (width & (width - 1)) == 0;
+        heightValid = (height & (height - 1)) == 0;
+        break;
+    }
+    case GL_ETC1_RGB8_OES: {
+        widthValid = true;
+        heightValid = true;
+        break;
     }
     default:
         return false;
     }
+
+    if (!widthValid || !heightValid) {
+        synthesizeGLError(GL_INVALID_OPERATION, functionName, "width or height invalid for level");
+        return false;
+    }
+
+    return true;
 }
 
 bool WebGLRenderingContextBase::validateCompressedTexSubDimensions(const char* functionName, GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, WebGLTexture* tex)
@@ -4897,6 +4920,28 @@ bool WebGLRenderingContextBase::validateCompressedTexSubDimensions(const char* f
         }
         return validateCompressedTexDimensions(functionName, TexSubImage2D, target, level, width, height, format);
     }
+    case GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG:
+    case GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG:
+    case GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG:
+    case GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG: {
+        if ((xoffset != 0) || (yoffset != 0)) {
+            synthesizeGLError(GL_INVALID_OPERATION, functionName, "xoffset or yoffset must be zero");

[Ken Russell (switch to Gerrit), 2014/04/18 01:56:35]

"xoffset and yoffset" would be clearer.

+            return false;
+        }
+        if (width != tex->getWidth(target, level)
+            || height != tex->getHeight(target, level)) {
+            synthesizeGLError(GL_INVALID_OPERATION, functionName, "dimensions must match existing level");
+            return false;
+        }
+        return validateCompressedTexDimensions(functionName, TexSubImage2D, target, level, width, height, format);
+    }
+    case GC3D_COMPRESSED_ATC_RGB_AMD:
+    case GC3D_COMPRESSED_ATC_RGBA_EXPLICIT_ALPHA_AMD:
+    case GC3D_COMPRESSED_ATC_RGBA_INTERPOLATED_ALPHA_AMD:
+    case GL_ETC1_RGB8_OES: {
+        synthesizeGLError(GL_INVALID_OPERATION, functionName, "not valid for this format");

[Zhenyao Mo, 2014/04/17 22:40:27]

I think if these formats are not supported, they should be caught while checking
the format (in this case, whether it's matching the internal format) and an
error should be generated there.  Here probably you can just ASSERT(FALSE),
assuming format checking is before this.

Also, while reading this, I realized validateCompressedTexFormat() doesn't
generate an error message, which is a bug.

[Ken Russell (switch to Gerrit), 2014/04/18 01:56:35]

I think this is here because texSubImage2D isn't supported for these compressed
texture formats.

+        return false;
+    }
     default:
         return false;
     }