From 1cc0dba24348c95f550567a81fc8f4e4532bfb09 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20H=C3=B6glund?= <fredrik@kde.org>
Date: Sun, 24 Mar 2013 17:00:11 +0100
Subject: [PATCH] kwin/blur: Upload the geometry for both passes at the same
 time

Reviewed-by: Philipp Knechtges <philipp-dev@knechtges.com>
---
 effects/blur/blur.cpp | 46 ++++++++++++++++++++++++++++++++-----------
 effects/blur/blur.h   |  3 ++-
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/effects/blur/blur.cpp b/effects/blur/blur.cpp
index 9b4f066fea..985493077d 100644
--- a/effects/blur/blur.cpp
+++ b/effects/blur/blur.cpp
@@ -226,13 +226,8 @@ QRegion BlurEffect::blurRegion(const EffectWindow *w) const
     return region;
 }
 
-void BlurEffect::drawRegion(const QRegion &region)
+void BlurEffect::uploadRegion(QVector2D *&map, const QRegion &region)
 {
-    const int vertexCount = region.rectCount() * 6;
-    GLVertexBuffer *vbo = GLVertexBuffer::streamingBuffer();
-
-    QVector2D *map = (QVector2D *) vbo->map(vertexCount * sizeof(QVector2D));
-
     foreach (const QRect &r, region.rects()) {
         const QVector2D topLeft(r.x(), r.y());
         const QVector2D topRight(r.x() + r.width(), r.y());
@@ -249,7 +244,15 @@ void BlurEffect::drawRegion(const QRegion &region)
         *(map++) = bottomRight;
         *(map++) = topRight;
     }
+}
 
+void BlurEffect::uploadGeometry(GLVertexBuffer *vbo, const QRegion &horizontal, const QRegion &vertical)
+{
+    const int vertexCount = (horizontal.rectCount() + vertical.rectCount()) * 6;
+
+    QVector2D *map = (QVector2D *) vbo->map(vertexCount * sizeof(QVector2D));
+    uploadRegion(map, horizontal);
+    uploadRegion(map, vertical);
     vbo->unmap();
 
     const GLVertexAttrib layout[] = {
@@ -257,9 +260,7 @@ void BlurEffect::drawRegion(const QRegion &region)
         { VA_TexCoord, 2, GL_FLOAT, 0 }
     };
 
-    vbo->setVertexCount(vertexCount);
     vbo->setAttribLayout(layout, 2, sizeof(QVector2D));
-    vbo->render(GL_TRIANGLES);
 }
 
 void BlurEffect::prePaintScreen(ScreenPrePaintData &data, int time)
@@ -443,6 +444,11 @@ void BlurEffect::doBlur(const QRegion& shape, const QRect& screen, const float o
     const QRegion expanded = expand(shape) & screen;
     const QRect r = expanded.boundingRect();
 
+    // Upload geometry for the horizontal and vertical passes
+    GLVertexBuffer *vbo = GLVertexBuffer::streamingBuffer();
+    uploadGeometry(vbo, expanded, shape);
+    vbo->bindArrays();
+
     // Create a scratch texture and copy the area in the back buffer that we're
     // going to blur into it
     GLTexture scratch(r.width(), r.height());
@@ -475,7 +481,7 @@ void BlurEffect::doBlur(const QRegion& shape, const QRect& screen, const float o
     loadMatrix(textureMatrix);
     shader->setTextureMatrix(textureMatrix);
 
-    drawRegion(expanded);
+    vbo->draw(GL_TRIANGLES, 0, expanded.rectCount() * 6);
 
     GLRenderTarget::popRenderTarget();
     scratch.unbind();
@@ -503,7 +509,8 @@ void BlurEffect::doBlur(const QRegion& shape, const QRect& screen, const float o
     loadMatrix(textureMatrix);
     shader->setTextureMatrix(textureMatrix);
 
-    drawRegion(shape);
+    vbo->draw(GL_TRIANGLES, expanded.rectCount() * 6, shape.rectCount() * 6);
+    vbo->unbindArrays();
 
 #ifdef KWIN_HAVE_OPENGL_1
     if (effects->compositingType() == OpenGL1Compositing) {
@@ -599,6 +606,20 @@ void BlurEffect::doCachedBlur(EffectWindow *w, const QRegion& region, const floa
     const QRegion updateBackground = damagedRegion & region;
     const QRegion validUpdate = damagedRegion - expand(damagedRegion - region);
 
+    const QRegion horizontal = validUpdate.isEmpty() ? QRegion() : (updateBackground & screen);
+    const QRegion vertical   = blurredRegion & region;
+
+    const int horizontalOffset = 0;
+    const int horizontalCount = horizontal.rectCount() * 6;
+
+    const int verticalOffset = horizontalCount;
+    const int verticalCount = vertical.rectCount() * 6;
+
+    GLVertexBuffer *vbo = GLVertexBuffer::streamingBuffer();
+    uploadGeometry(vbo, horizontal, vertical);
+
+    vbo->bindArrays();
+
     if (!validUpdate.isEmpty()) {
         const QRect updateRect = (expand(updateBackground) & expanded).boundingRect();
         // First we have to copy the background from the frontbuffer
@@ -633,7 +654,7 @@ void BlurEffect::doCachedBlur(EffectWindow *w, const QRegion& region, const floa
 #endif
         shader->setTextureMatrix(textureMatrix);
 
-        drawRegion(updateBackground & screen);
+        vbo->draw(GL_TRIANGLES, horizontalOffset, horizontalCount);
 
         GLRenderTarget::popRenderTarget();
         tex.unbind();
@@ -674,7 +695,8 @@ void BlurEffect::doCachedBlur(EffectWindow *w, const QRegion& region, const floa
 #endif
     shader->setTextureMatrix(textureMatrix);
 
-    drawRegion(blurredRegion & region);
+    vbo->draw(GL_TRIANGLES, verticalOffset, verticalCount);
+    vbo->unbindArrays();
 
 #ifdef KWIN_HAVE_OPENGL_1
     if (effects->compositingType() == OpenGL1Compositing) {
diff --git a/effects/blur/blur.h b/effects/blur/blur.h
index 396e3e6c11..d12c692016 100644
--- a/effects/blur/blur.h
+++ b/effects/blur/blur.h
@@ -69,9 +69,10 @@ private:
     QRegion blurRegion(const EffectWindow *w) const;
     bool shouldBlur(const EffectWindow *w, int mask, const WindowPaintData &data) const;
     void updateBlurRegion(EffectWindow *w) const;
-    void drawRegion(const QRegion &region);
     void doBlur(const QRegion &shape, const QRect &screen, const float opacity);
     void doCachedBlur(EffectWindow *w, const QRegion& region, const float opacity);
+    void uploadRegion(QVector2D *&map, const QRegion &region);
+    void uploadGeometry(GLVertexBuffer *vbo, const QRegion &horizontal, const QRegion &vertical);
 
 private:
     BlurShader *shader;