glutSwapBuffers implicitly does a glFinish when swapping back to the front
buffer. We now issue a glFinish when not issuing SwapBuffers to ensure
the pipeline is complete.
(Problem found with Chromium).
diff --git a/progs/demos/readpix.c b/progs/demos/readpix.c
index d0c46a2..3b13bb2 100644
--- a/progs/demos/readpix.c
+++ b/progs/demos/readpix.c
@@ -1,4 +1,4 @@
-/* $Id: readpix.c,v 1.5 2002/04/22 16:03:37 brianp Exp $ */
+/* $Id: readpix.c,v 1.6 2002/05/02 09:15:22 alanh Exp $ */
/*
* glReadPixels and glCopyPixels test
@@ -34,7 +34,7 @@
#define ReadType GL_UNSIGNED_BYTE
#endif
#if 1
-static GLenum ReadFormat = GL_RGBA;
+static GLenum ReadFormat = GL_DEPTH_COMPONENT; /*GL_RGBA; */
static GLenum ReadType = GL_UNSIGNED_BYTE;
#endif
#if 0
@@ -111,6 +111,8 @@
glRasterPos2i(APosX, APosY);
glEnable(GL_DITHER);
SetupPixelTransfer(GL_FALSE);
+ glDrawBuffer(GL_AUX0);
+ glReadBuffer(GL_AUX0);
glDrawPixels(ImgWidth, ImgHeight, ImgFormat, GL_UNSIGNED_BYTE, Image);
/* do readpixels, drawpixels */
@@ -152,10 +154,12 @@
glRasterPos2i(CPosX, CPosY);
glDisable(GL_DITHER);
SetupPixelTransfer(ScaleAndBias);
- glCopyPixels(APosX, APosY, ImgWidth, ImgHeight, GL_COLOR);
+ glCopyPixels(APosX, APosY, ImgWidth, ImgHeight, GL_DEPTH);
if (!DrawFront)
glutSwapBuffers();
+ else
+ glFinish();
}
@@ -186,12 +190,12 @@
case 'f':
DrawFront = !DrawFront;
if (DrawFront) {
- glDrawBuffer(GL_FRONT);
- glReadBuffer(GL_FRONT);
+ glDrawBuffer(GL_AUX0);
+ glReadBuffer(GL_AUX0);
}
else {
- glDrawBuffer(GL_BACK);
- glReadBuffer(GL_BACK);
+ glDrawBuffer(GL_AUX0);
+ glReadBuffer(GL_AUX0);
}
printf("glDrawBuffer(%s)\n", DrawFront ? "GL_FRONT" : "GL_BACK");
break;