Ensure integer attributes get configured properly

For joint indices.

Change-Id: If3de9c6e7053a5f445604e776f73e2ff843b0be8
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

3 files changed, 24 insertions, 13 deletions

diff --git a/src/render/backend/renderer.cpp b/src/render/backend/renderer.cpp
index df8664f3e..bf34842d1 100644
--- a/src/render/backend/renderer.cpp
+++ b/src/render/backend/renderer.cpp
@@ -1820,16 +1820,16 @@ bool Renderer::updateVAOWithAttributes(Geometry *geometry,
             if ((attributeWasDirty = attribute->isDirty()) == true || forceUpdate) {
                 // Find the location for the attribute
                 const QVector<ShaderAttribute> shaderAttributes = shader->attributes();
-                int attributeLocation = -1;
+                const ShaderAttribute *attributeDescription = nullptr;
                 for (const ShaderAttribute &shaderAttribute : shaderAttributes) {
                     if (shaderAttribute.m_nameId == attribute->nameId()) {
-                        attributeLocation = shaderAttribute.m_location;
+                        attributeDescription = &shaderAttribute;
                         break;
                     }
                 }
-                if (attributeLocation < 0)
+                if (!attributeDescription || attributeDescription->m_location < 0)
                     return false;
-                m_graphicsContext->specifyAttribute(attribute, buffer, attributeLocation);
+                m_graphicsContext->specifyAttribute(attribute, buffer, attributeDescription);
             }
         }
 
diff --git a/src/render/graphicshelpers/graphicscontext.cpp b/src/render/graphicshelpers/graphicscontext.cpp
index e480d0aa7..7910c828a 100644
--- a/src/render/graphicshelpers/graphicscontext.cpp
+++ b/src/render/graphicshelpers/graphicscontext.cpp
@@ -1272,13 +1272,17 @@ void GraphicsContext::enableAttribute(const VAOVertexAttribute &attr)
     Q_ASSERT(buf);
     bindGLBuffer(buf, attr.bufferType);
 
-    QOpenGLShaderProgram *prog = activeShader();
-    prog->enableAttributeArray(attr.location);
-    prog->setAttributeBuffer(attr.location,
-                             attr.dataType,
-                             attr.byteOffset,
-                             attr.vertexSize,
-                             attr.byteStride);
+    // Don't use QOpenGLShaderProgram::setAttributeBuffer() because of QTBUG-43199.
+    // Use the introspection data and set the attribute explicitly
+    m_glHelper->enableVertexAttributeArray(attr.location);
+    m_glHelper->vertexAttributePointer(attr.shaderDataType,
+                                       attr.location,
+                                       attr.vertexSize,
+                                       attr.dataType,
+                                       GL_TRUE, // TODO: Support normalization property on QAttribute
+                                       attr.byteStride,
+                                       reinterpret_cast<const void *>(qintptr(attr.byteOffset)));
+
 
     // Done by the helper if it supports it
     if (attr.divisor != 0)
@@ -1403,8 +1407,11 @@ void GraphicsContext::applyUniform(const ShaderUniform &description, const Unifo
 }
 
 // Note: needs to be called while VAO is bound
-void GraphicsContext::specifyAttribute(const Attribute *attribute, Buffer *buffer, int location)
+void GraphicsContext::specifyAttribute(const Attribute *attribute,
+                                       Buffer *buffer,
+                                       const ShaderAttribute *attributeDescription)
 {
+    const int location = attributeDescription->m_location;
     if (location < 0) {
         qCWarning(Backend) << "failed to resolve location for attribute:" << attribute->name();
         return;
@@ -1440,6 +1447,7 @@ void GraphicsContext::specifyAttribute(const Attribute *attribute, Buffer *buffe
         attr.vertexSize = attribute->vertexSize() / attrCount;
         attr.byteStride = attribute->byteStride() + (attrCount * attrCount * typeSize);
         attr.divisor = attribute->divisor();
+        attr.shaderDataType = attributeDescription->m_type;
 
         enableAttribute(attr);
 
diff --git a/src/render/graphicshelpers/graphicscontext_p.h b/src/render/graphicshelpers/graphicscontext_p.h
index f1dc176f8..9252bb467 100644
--- a/src/render/graphicshelpers/graphicscontext_p.h
+++ b/src/render/graphicshelpers/graphicscontext_p.h
@@ -157,7 +157,9 @@ public:
 
     void setRenderer(Renderer *renderer);
 
-    void specifyAttribute(const Attribute *attribute, Buffer *buffer, int attributeLocation);
+    void specifyAttribute(const Attribute *attribute,
+                          Buffer *buffer,
+                          const ShaderAttribute *attributeDescription);
     void specifyIndices(Buffer *buffer);
     void updateBuffer(Buffer *buffer);
     QByteArray downloadBufferContent(Buffer *buffer);
@@ -324,6 +326,7 @@ private:
         uint vertexSize;
         uint byteStride;
         uint divisor;
+        GLenum shaderDataType;
     };
 
     using VAOIndexAttribute = HGLBuffer;