Implement WEBGL_shared_resources

Source/core/html/canvas/WebGLProgram.cpp

Index: Source/core/html/canvas/WebGLProgram.cpp
diff --git a/Source/core/html/canvas/WebGLProgram.cpp b/Source/core/html/canvas/WebGLProgram.cpp
index 5581744f8bbc056fb5d9f67375f292393af78667..81327e2cb95ce4890a5dc49ba2928a8e024f1a54 100644
--- a/Source/core/html/canvas/WebGLProgram.cpp
+++ b/Source/core/html/canvas/WebGLProgram.cpp
@@ -64,39 +64,40 @@ void WebGLProgram::deleteObjectImpl(GraphicsContext3D* context3d, Platform3DObje
     }
 }
 
-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;
 }
 
@@ -172,7 +173,36 @@ void WebGLProgram::cacheActiveAttribLocations(GraphicsContext3D* context3d)
     }
 }
 
-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());
+        // This loop makes a chain of locations for elements of a uniform array. Given the location of any
+        // element in the array you can get the next element's location from 'nextLocation'. If 'nextLocation'
+        // is -1 it's the last element.
+        for (int j = 0; location >= 0 && j < info.size; ++j) {
+            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;
@@ -180,15 +210,35 @@ void WebGLProgram::cacheInfoIfNeeded()
     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::conditionallyRecordTextureUnitsAssignedToSamplers(WebGLRenderingContext* context, GC3Dint location, GC3Dsizei size, const GC3Dint* v)
+{
+    cacheInfoIfNeeded(context);
+
+    // Locations are stored such that each element of a uniform array has a "nextLocation" field
+    // that gives the location of the next element in the array. So, given the location of any element
+    // you can fill out subsequent elements by following 'nextLocation' until the nextLocation is < 0.
+    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;
+    }
+}
+
 }