From 513f396c7a888473a32cf212f1ce969fe38fdf2e Mon Sep 17 00:00:00 2001
From: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Thu, 28 Oct 2010 16:18:15 -0700
Subject: Wayland: use correct viewport for swapBuffers and correct coords

We're drawing into the parent, so we need to use the parent's geometry
for the GL viewport, or we may not be able to draw it.  We also need to
use the parent width & height when checking whether to normalize to 1.0
or -1.0 in the coord transform calculations.
---
 .../platforms/wayland/qwaylandintegration.cpp      | 43 ++++++++++++++--------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/src/plugins/platforms/wayland/qwaylandintegration.cpp b/src/plugins/platforms/wayland/qwaylandintegration.cpp
index 4767f56..b8b7c2f 100644
--- a/src/plugins/platforms/wayland/qwaylandintegration.cpp
+++ b/src/plugins/platforms/wayland/qwaylandintegration.cpp
@@ -542,6 +542,7 @@ void QWaylandGLContext::makeCurrent()
 
     eglMakeCurrent(mDisplay->eglDisplay(), 0, 0, mBuffer->mContext);
 
+    glViewport(0, 0, geometry.width(), geometry.height());
     glBindFramebuffer(GL_FRAMEBUFFER, mBuffer->mFbo);
     glBindTexture(GL_TEXTURE_2D, mBuffer->mTexture);
     glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, mBuffer->mImage);
@@ -553,6 +554,12 @@ void QWaylandGLContext::doneCurrent()
 {
 }
 
+/* drawTexture - Draw from a texture into a the current framebuffer
+ * @rect: GL normalized coords for drawing (between -1.0f and 1.0f)
+ * @tex_id: texture source
+ * @texSize: size of source rectangle in Qt coords
+ * @br: bounding rect for drawing
+ */
 static void drawTexture(const QRectF &rect, GLuint tex_id,
 			const QSize &texSize, const QRectF &br)
 {
@@ -585,6 +592,11 @@ static void drawTexture(const QRectF &rect, GLuint tex_id,
 
     glBindTexture(GL_TEXTURE_2D, tex_id);
 
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
     glEnableVertexAttribArray(QT_VERTEX_COORDS_ATTR);
     glEnableVertexAttribArray(QT_TEXTURE_COORDS_ATTR);
     glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
@@ -620,9 +632,6 @@ void QWaylandGLContext::swapBuffers()
 
     glDisable(GL_DEPTH_TEST);
 
-    w = geometry.width() ? geometry.width() : 1.0f;
-    h = geometry.height() ? geometry.height() : 1.0f;
-
     /* These need to be generated against the src context */
     if (!parentFbo)
 	glGenFramebuffers(1, &parentFbo);
@@ -636,32 +645,36 @@ void QWaylandGLContext::swapBuffers()
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 			      GL_RENDERBUFFER, parentRbo);
     glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, mBuffer->mImage);
-    glViewport(0, 0, geometry.width(), geometry.height());
+    glViewport(0, 0, parentGeometry.width(), parentGeometry.height());
 
     blitProgram = QGLEngineSharedShaders::shadersForContext(QGLContext::currentContext())->blitProgram();
     blitProgram->bind();
     blitProgram->setUniformValue("imageTexture", 0);
 
-    // The shader manager's blit program does not multiply the
-    // vertices by the pmv matrix, so we need to do the effect
-    // of the orthographic projection here ourselves.
+    /* Transform the target rect to the appropriate coords on the parent */
+    w = parentGeometry.width();
+    h = parentGeometry.height();
+
     r.setLeft((geometry.left() / w) * 2.0f - 1.0f);
-    if (geometry.right() == (geometry.width() - 1))
+    if (geometry.right() == (parentGeometry.width() - 1))
 	r.setRight(1.0f);
     else
 	r.setRight((geometry.right() / w) * 2.0f - 1.0f);
-    r.setBottom((geometry.top() / h) * 2.0f - 1.0f);
-    if (geometry.bottom() == (geometry.height() - 1))
-	r.setTop(1.0f);
+
+    r.setTop((geometry.top() / h) * 2.0f - 1.0f);
+    if (geometry.bottom() == (parentGeometry.height() - 1))
+       r.setBottom(-1.0f);
     else
-	r.setTop((geometry.bottom() / h) * 2.0f - 1.0f);
+	r.setBottom((geometry.bottom() / h) * 2.0f - 1.0f);
 
-    drawTexture(r, mBuffer->mTexture, mWindow->widget()->size(), geometry);
+    drawTexture(r, mBuffer->mTexture, mParentWindow->widget()->size(), parentGeometry);
 
-    wl_surface_damage(mParentWindow->surface(), 0, 0,
-		      geometry.width(), geometry.height());
+    wl_surface_damage(mParentWindow->surface(), geometry.left(), geometry.top(),
+		      geometry.right(), geometry.bottom());
     /* restore things to the last valid GL state */
     makeCurrent();
+    /* hack: avoid tight swapBuffers loops */
+    usleep(20000);
 }
 
 void *QWaylandGLContext::getProcAddress(const QString &string)
-- 
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