From 64bbd69d75c7b90500c3fe57e66221684d5a8d92 Mon Sep 17 00:00:00 2001
From: Rhys Weatherley <rhys.weatherley@nokia.com>
Date: Fri, 24 Jul 2009 11:08:23 +1000
Subject: Make it easier to change custom shaders.

---
 src/opengl/gl2paintengineex/qglcustomshaderstage.cpp   | 17 +++++++++++++++++
 src/opengl/gl2paintengineex/qglcustomshaderstage_p.h   |  1 +
 src/opengl/gl2paintengineex/qglengineshadermanager.cpp |  7 +++++++
 src/opengl/gl2paintengineex/qglengineshadermanager_p.h |  1 +
 4 files changed, 26 insertions(+)

diff --git a/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp b/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp
index efc3b93..bcd9f27 100644
--- a/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp
+++ b/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp
@@ -93,6 +93,23 @@ bool QGLCustomShaderStage::setOnPainter(QPainter* p)
     return true;
 }
 
+void QGLCustomShaderStage::removeFromPainter(QPainter* p)
+{
+    Q_D(QGLCustomShaderStage);
+    if (p->paintEngine()->type() != QPaintEngine::OpenGL2)
+        return;
+
+    // Might as well go through the paint engine to get to the context
+    const QGLContext* ctx = static_cast<QGL2PaintEngineEx*>(p->paintEngine())->context();
+    d->m_manager = QGLEngineShaderManager::managerForContext(ctx);
+    Q_ASSERT(d->m_manager);
+
+    // Just set the stage to null, don't call removeCustomStage().
+    // This should leave the program in a compiled/linked state
+    // if the next custom shader stage is this one again.
+    d->m_manager->setCustomStage(0);
+}
+
 const char* QGLCustomShaderStage::source()
 {
     Q_D(QGLCustomShaderStage);
diff --git a/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h b/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h
index 6e4ca1c..659f7ba 100644
--- a/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h
+++ b/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h
@@ -72,6 +72,7 @@ public:
 
     void setUniformsDirty();
     bool setOnPainter(QPainter*);
+    void removeFromPainter(QPainter*);
     const char* source();
 
 protected:
diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
index c110c50..6363212 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
@@ -86,6 +86,8 @@ QGLEngineShaderManager::QGLEngineShaderManager(QGLContext* context)
       maskType(NoMask),
       useTextureCoords(false),
       compositionMode(QPainter::CompositionMode_SourceOver),
+      customSrcStage(0),
+      customSrcStagePrev(0),
       blitShaderProg(0),
       simpleShaderProg(0),
       currentShaderProg(0)
@@ -311,6 +313,11 @@ void QGLEngineShaderManager::setCompositionMode(QPainter::CompositionMode mode)
 
 void QGLEngineShaderManager::setCustomStage(QGLCustomShaderStage* stage)
 {
+    // If the custom shader has changed, then destroy the previous compilation.
+    if (customSrcStagePrev && stage && customSrcStagePrev != stage)
+        removeCustomStage(customSrcStagePrev);
+
+    customSrcStagePrev = customSrcStage;
     customSrcStage = stage;
     shaderProgNeedsChanging = true;
 }
diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
index 15082c3..9d881cc 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
@@ -421,6 +421,7 @@ private:
     bool                        useTextureCoords;
     QPainter::CompositionMode   compositionMode;
     QGLCustomShaderStage*       customSrcStage;
+    QGLCustomShaderStage*       customSrcStagePrev;
 
     QGLShaderProgram*     blitShaderProg;
     QGLShaderProgram*     simpleShaderProg;
-- 
cgit v0.12