Track which vertex attrib arrays are enabled in QGLContextPrivate

The GL2 engine (and probably Qt/3D) needs to track which vertex
attribute arrays are currently enabled and which are disabled. As
this is per-context state, the logical place to track this is in the
context and not in the paint engine.

This patch also makes the GL2 engine's shader manager enable/disable
the appropriate attribute arrays for a given shader program when it
is used.

Reviewed-By: Kim

1 files changed, 31 insertions, 0 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 466e851..5bb62f7 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -1484,6 +1484,8 @@ void QGLContextPrivate::init(QPaintDevice *dev, const QGLFormat &format)
     current_fbo = 0;
     default_fbo = 0;
     active_engine = 0;
+    for (int i = 0; i < QT_GL_VERTEX_ARRAY_TRACKED_COUNT; ++i)
+        vertexAttributeArraysEnabledState[i] = false;
 }
 
 QGLContext* QGLContext::currentCtx = 0;
@@ -1874,6 +1876,35 @@ void QGLContextPrivate::cleanup()
 {
 }
 
+#define ctx q_ptr
+void QGLContextPrivate::setVertexAttribArrayEnabled(int arrayIndex, bool enabled)
+{
+    Q_ASSERT(arrayIndex < QT_GL_VERTEX_ARRAY_TRACKED_COUNT);
+    Q_ASSERT(glEnableVertexAttribArray);
+
+    if (vertexAttributeArraysEnabledState[arrayIndex] && !enabled)
+        glDisableVertexAttribArray(arrayIndex);
+
+    if (!vertexAttributeArraysEnabledState[arrayIndex] && enabled)
+        glEnableVertexAttribArray(arrayIndex);
+
+    vertexAttributeArraysEnabledState[arrayIndex] = enabled;
+}
+
+void QGLContextPrivate::syncGlState()
+{
+    Q_ASSERT(glEnableVertexAttribArray);
+    for (int i = 0; i < QT_GL_VERTEX_ARRAY_TRACKED_COUNT; ++i) {
+        if (vertexAttributeArraysEnabledState[i])
+            glEnableVertexAttribArray(i);
+        else
+            glDisableVertexAttribArray(i);
+    }
+
+}
+#undef ctx
+
+
 /*!
     \overload