Implement WEBGL_shared_resources

Source/core/html/canvas/WebGLProgram.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 46 matching lines @@
     if (m_vertexShader) {
         m_vertexShader->onDetached(context3d);
         m_vertexShader = 0;
     }
     if (m_fragmentShader) {
         m_fragmentShader->onDetached(context3d);
         m_fragmentShader = 0;
     }
 }
 
-unsigned WebGLProgram::numActiveAttribLocations()
+unsigned WebGLProgram::numActiveAttribLocations(WebGLRenderingContext* context)
 {
-    cacheInfoIfNeeded();
+    cacheInfoIfNeeded(context);
     return m_activeAttribLocations.size();
 }
 
-GC3Dint WebGLProgram::getActiveAttribLocation(GC3Duint index)
+GC3Dint WebGLProgram::getActiveAttribLocation(WebGLRenderingContext* context, GC3Duint index)
 {
-    cacheInfoIfNeeded();
-    if (index >= numActiveAttribLocations())
+    cacheInfoIfNeeded(context);
+    if (index >= numActiveAttribLocations(context))
         return -1;
     return m_activeAttribLocations[index];
 }
 
-bool WebGLProgram::isUsingVertexAttrib0()
+bool WebGLProgram::isUsingVertexAttrib0(WebGLRenderingContext* context)
 {
-    cacheInfoIfNeeded();
-    for (unsigned ii = 0; ii < numActiveAttribLocations(); ++ii) {
-        if (!getActiveAttribLocation(ii))
+    cacheInfoIfNeeded(context);
+    unsigned numLocations = numActiveAttribLocations(context);
+    for (unsigned ii = 0; ii < numLocations; ++ii) {
+        if (!getActiveAttribLocation(context, ii))
             return true;
     }
     return false;
 }
 
-bool WebGLProgram::getLinkStatus()
+bool WebGLProgram::getLinkStatus(WebGLRenderingContext* context)
 {
-    cacheInfoIfNeeded();
+    cacheInfoIfNeeded(context);
     return m_linkStatus;
 }
 
-void WebGLProgram::setLinkStatus(bool status)
+void WebGLProgram::setLinkStatus(WebGLRenderingContext* context, bool status)
 {
-    cacheInfoIfNeeded();
+    cacheInfoIfNeeded(context);
     m_linkStatus = status;
 }
 
 void WebGLProgram::increaseLinkCount()
 {
     ++m_linkCount;
     m_infoValid = false;
 }
 
 WebGLShader* WebGLProgram::getAttachedShader(GC3Denum type)
@@ skipping 55 matching lines @@
     GC3Dint numAttribs = 0;
     context3d->getProgramiv(object(), GraphicsContext3D::ACTIVE_ATTRIBUTES, &numAttribs);
     m_activeAttribLocations.resize(static_cast<size_t>(numAttribs));
     for (int i = 0; i < numAttribs; ++i) {
         ActiveInfo info;
         context3d->getActiveAttrib(object(), i, info);
         m_activeAttribLocations[i] = context3d->getAttribLocation(object(), info.name.charactersWithNullTermination());
     }
 }
 
-void WebGLProgram::cacheInfoIfNeeded()
+void WebGLProgram::cacheSamplerLocations(GraphicsContext3D* context3d)
+{
+    m_samplerLocationToTextureUnit.clear();
+
+    GC3Dint numUniforms = 0;
+    context3d->getProgramiv(object(), GraphicsContext3D::ACTIVE_UNIFORMS, &numUniforms);
+    for (int i = 0; i < numUniforms; ++i) {
+        ActiveInfo info;
+        context3d->getActiveUniform(object(), i, info);
+        if (info.type != GraphicsContext3D::SAMPLER_2D && info.type != GraphicsContext3D::SAMPLER_CUBE) {
+            continue;
+        }
+        GC3Dint location = context3d->getUniformLocation(object(), info.name.charactersWithNullTermination());
+        for (int j = 0; location >= 0 && j < info.size; ++j) {

[Ken Russell (switch to Gerrit), 2013/06/19 03:51:24]

This inner loop is tricky to understand. Can you add a comment saying that the
point of the loop is to chain together the locations of uniform sampler arrays?

[greggman, 2013/06/21 19:54:21]

Done.

+            GC3Dint nextLocation = -1;
+            if (j < info.size - 1) {
+                String elementName(info.name + "[" + String::number(j + 1) + "]");
+                nextLocation = context3d->getUniformLocation(object(), elementName.charactersWithNullTermination());
+            }
+            // Add one because HashMap can't store 0
+            m_samplerLocationToTextureUnit.add(location + 1, SamplerInfo(info.type, nextLocation));
+            location = nextLocation;
+        }
+    }
+}
+
+void WebGLProgram::cacheInfoIfNeeded(WebGLRenderingContext* context)
 {
     if (m_infoValid)
         return;
 
     if (!object())
         return;
 
-    GraphicsContext3D* context = getAGraphicsContext3D();
+    GraphicsContext3D* gc3d = context->graphicsContext3D();
     if (!context)
         return;
     GC3Dint linkStatus = 0;
-    context->getProgramiv(object(), GraphicsContext3D::LINK_STATUS, &linkStatus);
+    gc3d->getProgramiv(object(), GraphicsContext3D::LINK_STATUS, &linkStatus);
     m_linkStatus = linkStatus;
-    if (m_linkStatus)
-        cacheActiveAttribLocations(context);
+    if (m_linkStatus) {
+        cacheActiveAttribLocations(gc3d);
+        cacheSamplerLocations(gc3d);
+    }
     m_infoValid = true;
 }
 
+void WebGLProgram::setSampler(WebGLRenderingContext* context, GC3Dint location, GC3Dsizei size, const GC3Dint* v)
+{
+    cacheInfoIfNeeded(context);
+
+    for (; location >= 0 && size > 0; --size) {
+        // Add one because HashMap can't store 0.
+        SamplerTextureUnitMap::iterator it = m_samplerLocationToTextureUnit.find(location + 1);
+        if (it == m_samplerLocationToTextureUnit.end()) {
+            return;
+        }
+        it->value.unit = *v++;
+        location = it->value.nextLocation;

[Ken Russell (switch to Gerrit), 2013/06/19 03:51:24]

This chaining together of the locations of uniform sampler arrays is extremely
clever. I wonder whether anyone is going to understand it in the future...

[greggman, 2013/06/21 19:54:21]

added a comment. Or are you suggesting I should use another implementation?

+    }
 }
+
+}