Enable preloading/sharing of the overlap renderer's clip program.

This allows the cost to be payed once at startup, rather than
on the first frame of each renderer.

Change-Id: Ibcd0e2a3f15bf121ba139a7ac19b0df490116b0c
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

4 files changed, 40 insertions, 23 deletions

diff --git a/customcontext/context.cpp b/customcontext/context.cpp
index ba03e06..41de804 100644
--- a/customcontext/context.cpp
+++ b/customcontext/context.cpp
@@ -231,6 +231,24 @@ void Context::initialize(QOpenGLContext *context)
     }
 #endif
 
+#ifdef CUSTOMCONTEXT_OVERLAPRENDERER
+    if (m_overlapRenderer) {
+        m_clipProgram.addShaderFromSourceCode(QOpenGLShader::Vertex,
+                                            "attribute highp vec4 vCoord;       \n"
+                                            "uniform highp mat4 matrix;         \n"
+                                            "void main() {                      \n"
+                                            "    gl_Position = matrix * vCoord; \n"
+                                            "}");
+        m_clipProgram.addShaderFromSourceCode(QOpenGLShader::Fragment,
+                                            "void main() {                                   \n"
+                                            "    gl_FragColor = vec4(0.81, 0.83, 0.12, 1.0); \n" // Trolltech green ftw!
+                                            "}");
+        m_clipProgram.bindAttributeLocation("vCoord", 0);
+        m_clipProgram.link();
+        m_clipMatrixID = m_clipProgram.uniformLocation("matrix");
+    }
+#endif
+
 #ifdef CUSTOMCONTEXT_DEBUG
     qDebug("CustomContext: initialized..");
 #ifdef CUSTOMCONTEXT_MATERIALPRELOAD
@@ -303,8 +321,12 @@ QSGTexture *Context::createTexture(const QImage &image) const
 QSGRenderer *Context::createRenderer()
 {
 #ifdef CUSTOMCONTEXT_OVERLAPRENDERER
-    if (m_overlapRenderer)
-        return new OverlapRenderer::Renderer(this);
+    if (m_overlapRenderer) {
+        OverlapRenderer::Renderer *renderer =
+                new OverlapRenderer::Renderer(this);
+        renderer->setClipProgram(&m_clipProgram, m_clipMatrixID);
+        return renderer;
+    }
 #endif
     return QSGContext::createRenderer();
 }
diff --git a/customcontext/context.h b/customcontext/context.h
index 53bfb6f..72f2b87 100644
--- a/customcontext/context.h
+++ b/customcontext/context.h
@@ -97,6 +97,8 @@ private:
 
 #ifdef CUSTOMCONTEXT_OVERLAPRENDERER
     bool m_overlapRenderer;
+    QOpenGLShaderProgram m_clipProgram;
+    int m_clipMatrixID;
 #endif
 
 #ifdef CUSTOMCONTEXT_ANIMATIONDRIVER
diff --git a/customcontext/renderer/overlaprenderer.cpp b/customcontext/renderer/overlaprenderer.cpp
index c6f1a3e..b1d04e7 100644
--- a/customcontext/renderer/overlaprenderer.cpp
+++ b/customcontext/renderer/overlaprenderer.cpp
@@ -847,26 +847,16 @@ void Renderer::nodeChanged(QSGNode *node, QSGNode::DirtyState flags)
     }
 }
 
+void Renderer::setClipProgram(QOpenGLShaderProgram *program, int matrixID)
+{
+    clipProgram = program;
+    clipMatrixID = matrixID;
+}
+
 void Renderer::render()
 {
     PROFILE_BEGINFRAME();
 
-    if (!clipProgram.isLinked()) {
-        clipProgram.addShaderFromSourceCode(QOpenGLShader::Vertex,
-                                            "attribute highp vec4 vCoord;       \n"
-                                            "uniform highp mat4 matrix;         \n"
-                                            "void main() {                      \n"
-                                            "    gl_Position = matrix * vCoord; \n"
-                                            "}");
-        clipProgram.addShaderFromSourceCode(QOpenGLShader::Fragment,
-                                            "void main() {                                   \n"
-                                            "    gl_FragColor = vec4(0.81, 0.83, 0.12, 1.0); \n" // Trolltech green ftw!
-                                            "}");
-        clipProgram.bindAttributeLocation("vCoord", 0);
-        clipProgram.link();
-        clipMatrixID = clipProgram.uniformLocation("matrix");
-    }
-
     batchConfigs.clear();
     minBatchConfig = 0;
 
@@ -1641,8 +1631,9 @@ void Renderer::drawBatches()
                             glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
                             glDepthMask(GL_FALSE);
 
-                            clipProgram.bind();
-                            clipProgram.enableAttributeArray(0);
+                            Q_ASSERT(clipProgram);
+                            clipProgram->bind();
+                            clipProgram->enableAttributeArray(0);
 
                             currentClipType |= StencilClip;
                         }
@@ -1655,7 +1646,7 @@ void Renderer::drawBatches()
                         const QSGGeometry::Attribute *a = g->attributes();
                         glVertexAttribPointer(0, a->tupleSize, a->type, GL_FALSE, g->sizeOfVertex(), g->vertexData());
 
-                        clipProgram.setUniformValue(clipMatrixID, m);
+                        clipProgram->setUniformValue(clipMatrixID, m);
                         if (g->indexCount())
                             glDrawElements(g->drawingMode(), g->indexCount(), g->indexType(), g->indexData());
                         else
@@ -1669,7 +1660,7 @@ void Renderer::drawBatches()
                     clip = clip->clipList();
 
                     if (currentClipType & StencilClip) {
-                        clipProgram.disableAttributeArray(0);
+                        clipProgram->disableAttributeArray(0);
                         glStencilFunc(GL_EQUAL, m_current_stencil_value, 0xff); // stencil test, ref, test mask
                         glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP); // stencil fail, z fail, z pass
                         glStencilMask(0); // write mask
diff --git a/customcontext/renderer/overlaprenderer.h b/customcontext/renderer/overlaprenderer.h
index 8e089a7..9cd7567 100644
--- a/customcontext/renderer/overlaprenderer.h
+++ b/customcontext/renderer/overlaprenderer.h
@@ -332,6 +332,8 @@ public:
     void render();
     void nodeChanged(QSGNode *node, QSGNode::DirtyState flags);
 
+    void setClipProgram(QOpenGLShaderProgram *program, int matrixID);
+
 private:
 
     void buildRenderOrderList(QSGNode *node);
@@ -359,7 +361,7 @@ private:
     std::vector<VertexFormat *> m_vertexFormats;
     std::vector<RenderBatch> m_batches;
 
-    QOpenGLShaderProgram clipProgram;
+    QOpenGLShaderProgram *clipProgram;
     int clipMatrixID;
 
     int minBatchConfig;