Implement OES_texture_float_linear and OES_texture_half_float_linear extensions in WebGL.

Source/core/html/canvas/WebGLTexture.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 30 matching lines @@
 WebGLTexture::WebGLTexture(WebGLRenderingContext* ctx)
     : WebGLSharedObject(ctx)
     , m_target(0)
     , m_minFilter(GraphicsContext3D::NEAREST_MIPMAP_LINEAR)
     , m_magFilter(GraphicsContext3D::LINEAR)
     , m_wrapS(GraphicsContext3D::REPEAT)
     , m_wrapT(GraphicsContext3D::REPEAT)
     , m_isNPOT(false)
     , m_isComplete(false)
     , m_needToUseBlackTexture(false)
+    , m_isFloatType(false)
+    , m_isHalfFloatType(false)
 {
     setObject(ctx->graphicsContext3D()->createTexture());
 }
 
 WebGLTexture::~WebGLTexture()
 {
     deleteObject(0);
 }
 
 void WebGLTexture::setTarget(GC3Denum target, GC3Dint maxLevel)
@@ skipping 162 matching lines @@
     return false;
 }
 
 bool WebGLTexture::isNPOT() const
 {
     if (!object())
         return false;
     return m_isNPOT;
 }
 
-bool WebGLTexture::needToUseBlackTexture() const
+bool WebGLTexture::needToUseBlackTexture(TextureExtensionFlag flag) const
 {
     if (!object())
         return false;
-    return m_needToUseBlackTexture;
+    if (m_needToUseBlackTexture)
+        return true;
+    if ((m_isFloatType && !(flag & TextureFloatLinearExtensionEnabled)) || (m_isHalfFloatType && !(flag && TextureHalfFloatLinearExtensionEnabled))) {
+        if (m_magFilter != GraphicsContext3D::NEAREST || (m_minFilter != GraphicsContext3D::NEAREST && m_minFilter != GraphicsContext3D::NEAREST_MIPMAP_NEAREST))
+            return true;
+    }
+    return false;
 }
 
 void WebGLTexture::deleteObjectImpl(GraphicsContext3D* context3d, Platform3DObject object)
 {
     context3d->deleteTexture(object);
 }
 
 int WebGLTexture::mapTargetToIndex(GC3Denum target) const
 {
     if (m_target == GraphicsContext3D::TEXTURE_2D) {
@@ skipping 85 matching lines @@
                 if (!info.valid
                     || info.width != width || info.height != height
                     || info.internalFormat != info0.internalFormat || info.type != info0.type) {
                     m_isComplete = false;
                     break;
                 }
 
             }
         }
     }
+    m_isFloatType = false;
+    if (m_isComplete)
+        m_isFloatType = m_info[0][0].type == GraphicsContext3D::FLOAT;
+    else {
+        for (size_t ii = 0; ii < m_info.size(); ++ii) {
+            if (m_info[ii][0].type == GraphicsContext3D::FLOAT) {
+                m_isFloatType = true;
+                break;
+            }
+        }
+    }

[Ken Russell (switch to Gerrit), 2013/05/20 19:46:45]

OK. It still isn't clear to me that scanning through all of the faces is
necessary, but improving this further can be left for a future optimization.

+    m_isHalfFloatType = false;
+    if (m_isComplete)
+        m_isHalfFloatType = m_info[0][0].type == GraphicsContext3D::HALF_FLOAT_OES;
+    else {
+        for (size_t ii = 0; ii < m_info.size(); ++ii) {
+            if (m_info[ii][0].type == GraphicsContext3D::HALF_FLOAT_OES) {
+                m_isHalfFloatType = true;
+                break;
+            }
+        }
+    }
 
     m_needToUseBlackTexture = false;
     // NPOT
     if (m_isNPOT && ((m_minFilter != GraphicsContext3D::NEAREST && m_minFilter != GraphicsContext3D::LINEAR)
                      || m_wrapS != GraphicsContext3D::CLAMP_TO_EDGE || m_wrapT != GraphicsContext3D::CLAMP_TO_EDGE))
         m_needToUseBlackTexture = true;
     // Completeness
     if (!m_isComplete && m_minFilter != GraphicsContext3D::NEAREST && m_minFilter != GraphicsContext3D::LINEAR)
         m_needToUseBlackTexture = true;
 }
 
 const WebGLTexture::LevelInfo* WebGLTexture::getLevelInfo(GC3Denum target, GC3Dint level) const
 {
     if (!object() || !m_target)
         return 0;
     int targetIndex = mapTargetToIndex(target);
     if (targetIndex < 0 || targetIndex >= static_cast<int>(m_info.size()))
         return 0;
     if (level < 0 || level >= static_cast<GC3Dint>(m_info[targetIndex].size()))
         return 0;
     return &(m_info[targetIndex][level]);
 }
 
 }