Files
third_party_mesa3d/progs/trivial/tri-stencil.c
Robert Ellison 711f8a1dd9 CELL: stencil bug fixes
Two definitive bugs in stenciling were fixed.

The first, reversed registers in the generated Select Bytes (selb)
instruction, caused the stenciling INCR and DECR operations to
fail dramatically, putting new values in where old values were
supposed to be and vice versa.

The second caused stencil tiles to not be read and written from
main memory by the SPUs.  A per-spu flag, spu.read_depth, was used
to indicate whether the SPU should be reading depth tiles, and was set
only when depth was enabled.  A second flag, spu.read_stencil, was
set when stenciling was enabled, but never referenced.

As stenciling and depth are in the same tiles on the Cell, and there
is no corresponding TAG_WRITE_TILE_STENCIL to complement
TAG_WRITE_TILE_COLOR and TAG_WRITE_TILE_Z, I fixed this by
eliminating the unused "spu.read_stencil", renaming "spu.read_depth"
to "spu.read_depth_stencil", and setting it if either stenciling or
depth is enabled.

I also added an optimization to the fragment ops generation code,
that avoids calculating stencil values and/or stencil writemask
when the stencil operations are all KEEP.
2008-10-30 15:24:52 -06:00

159 lines
3.5 KiB
C

/*
* Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that (i) the above copyright notices and this permission notice appear in
* all copies of the software and related documentation, and (ii) the name of
* Silicon Graphics may not be used in any advertising or
* publicity relating to the software without the specific, prior written
* permission of Silicon Graphics.
*
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
* ANY KIND,
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <GL/glut.h>
static void Init(void)
{
}
static void Reshape(int width, int height)
{
glViewport(0, 0, (GLint)width, (GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-5.0, 5.0, -5.0, 5.0, -5.0, 5.0);
glMatrixMode(GL_MODELVIEW);
}
static void Key(unsigned char key, int x, int y)
{
switch (key) {
case 27:
printf("Exiting...\n");
exit(1);
case 'r':
printf("Redisplaying...\n");
glutPostRedisplay();
break;
default:
printf("No such key '%c'...\n", key);
break;
}
}
static void Draw(void)
{
glShadeModel(GL_FLAT);
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glClearStencil(0);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
}
glStencilMask(1);
glEnable(GL_STENCIL_TEST);
glStencilFunc(GL_ALWAYS, 1, 1);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
glColor3ub(200, 0, 0);
glBegin(GL_POLYGON);
glVertex3i(-4, -4, 0);
glVertex3i( 4, -4, 0);
glVertex3i( 0, 4, 0);
glEnd();
#if 1
glStencilFunc(GL_EQUAL, 1, 1);
glStencilOp(GL_INCR, GL_KEEP, GL_DECR);
glColor3ub(0, 200, 0);
glBegin(GL_POLYGON);
glVertex3i(3, 3, 0);
glVertex3i(-3, 3, 0);
glVertex3i(-3, -3, 0);
glVertex3i(3, -3, 0);
glEnd();
#endif
#if 1
glStencilFunc(GL_EQUAL, 1, 1);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
glColor3ub(0, 0, 200);
glBegin(GL_POLYGON);
glVertex3f(2.5, 2.5, 0);
glVertex3f(-2.5, 2.5, 0);
glVertex3f(-2.5, -2.5, 0);
glVertex3f(2.5, -2.5, 0);
glEnd();
#endif
glFlush();
}
static GLenum Args(int argc, char **argv)
{
GLint i;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-dr") == 0) {
} else {
printf("%s (Bad option).\n", argv[i]);
return GL_FALSE;
}
}
return GL_TRUE;
}
int main(int argc, char **argv)
{
GLenum type;
glutInit(&argc, argv);
if (Args(argc, argv) == GL_FALSE) {
exit(1);
}
glutInitWindowPosition(0, 0);
glutInitWindowSize( 300, 300);
type = GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH | GLUT_STENCIL;
glutInitDisplayMode(type);
if (glutCreateWindow("Stencil Test") == GL_FALSE) {
exit(1);
}
Init();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutDisplayFunc(Draw);
glutMainLoop();
return 0;
}