WebGL 2: add types into glReadPixels

Source/modules/webgl/WebGLRenderingContextBase.cpp

Index: Source/modules/webgl/WebGLRenderingContextBase.cpp
diff --git a/Source/modules/webgl/WebGLRenderingContextBase.cpp b/Source/modules/webgl/WebGLRenderingContextBase.cpp
index c18ea0b24ac9d1e3afc0d584c14def2d679e99a1..c9b3dec3353f7d7bb3e6d17f498862f2563168ec 100644
--- a/Source/modules/webgl/WebGLRenderingContextBase.cpp
+++ b/Source/modules/webgl/WebGLRenderingContextBase.cpp
@@ -3709,35 +3709,13 @@ bool WebGLRenderingContextBase::validateReadPixelsFormatTypeCombination(GLenum f
     return true;
 }
 
-void WebGLRenderingContextBase::readPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, DOMArrayBufferView* pixels)
+DOMArrayBufferView::ViewType WebGLRenderingContextBase::readPixelsExpectedArrayBufferViewType(GLenum type)
 {
-    if (isContextLost())
-        return;
-    // Due to WebGL's same-origin restrictions, it is not possible to
-    // taint the origin using the WebGL API.
-    ASSERT(canvas()->originClean());
-    // Validate input parameters.
-    if (!pixels) {
-        synthesizeGLError(GL_INVALID_VALUE, "readPixels", "no destination ArrayBufferView");
-        return;
-    }
-    if (!validateReadPixelsFormatAndType(format, type))
-        return;
-    GLenum readBufferInternalFormat = 0, readBufferType = 0;
-    WebGLFramebuffer* readFramebufferBinding = nullptr;
-    if (!validateReadBufferAndGetInfo("readPixels", readFramebufferBinding, &readBufferInternalFormat, &readBufferType))
-        return;
-    if (!validateReadPixelsFormatTypeCombination(format, type, readBufferInternalFormat, readBufferType))
-        return;
-
     DOMArrayBufferView::ViewType expectedViewType;

[Zhenyao Mo, 2015/08/14 16:07:42]

nit: you don't need this expectedViewType.  You can just return in each case,
saving one extra copying (although that's trivia).

     switch (type) {
     case GL_UNSIGNED_BYTE:
         expectedViewType = DOMArrayBufferView::TypeUint8;
         break;
-    case GL_BYTE:
-        expectedViewType = DOMArrayBufferView::TypeInt8;
-        break;
     case GL_UNSIGNED_SHORT_5_6_5:
     case GL_UNSIGNED_SHORT_4_4_4_4:
     case GL_UNSIGNED_SHORT_5_5_5_1:
@@ -3746,24 +3724,39 @@ void WebGLRenderingContextBase::readPixels(GLint x, GLint y, GLsizei width, GLsi
     case GL_FLOAT:
         expectedViewType = DOMArrayBufferView::TypeFloat32;
         break;
-    case GL_HALF_FLOAT:
     case GL_HALF_FLOAT_OES:
         expectedViewType = DOMArrayBufferView::TypeUint16;
         break;
-    case GL_UNSIGNED_INT:
-    case GL_UNSIGNED_INT_2_10_10_10_REV:
-    case GL_UNSIGNED_INT_10F_11F_11F_REV:
-    case GL_UNSIGNED_INT_5_9_9_9_REV:
-        expectedViewType = DOMArrayBufferView::TypeUint32;
-        break;
-    case GL_INT:
-        expectedViewType = DOMArrayBufferView::TypeInt32;
-        break;
     default:
         ASSERT_NOT_REACHED();
         expectedViewType = DOMArrayBufferView::TypeUint8;
         break;
     }
+    return expectedViewType;
+}
+
+void WebGLRenderingContextBase::readPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, DOMArrayBufferView* pixels)
+{
+    if (isContextLost())
+        return;
+    // Due to WebGL's same-origin restrictions, it is not possible to
+    // taint the origin using the WebGL API.
+    ASSERT(canvas()->originClean());
+    // Validate input parameters.
+    if (!pixels) {
+        synthesizeGLError(GL_INVALID_VALUE, "readPixels", "no destination ArrayBufferView");
+        return;
+    }
+    if (!validateReadPixelsFormatAndType(format, type))
+        return;
+    GLenum readBufferInternalFormat = 0, readBufferType = 0;
+    WebGLFramebuffer* readFramebufferBinding = nullptr;
+    if (!validateReadBufferAndGetInfo("readPixels", readFramebufferBinding, &readBufferInternalFormat, &readBufferType))
+        return;
+    if (!validateReadPixelsFormatTypeCombination(format, type, readBufferInternalFormat, readBufferType))
+        return;
+
+    DOMArrayBufferView::ViewType expectedViewType = readPixelsExpectedArrayBufferViewType(type);
     // Validate array type against pixel type.
     if (pixels->type() != expectedViewType) {
         synthesizeGLError(GL_INVALID_OPERATION, "readPixels", "ArrayBufferView was the wrong type for the pixel format");