demos: added progs/glsl/samplers.c to test all available texture samplers
This commit is contained in:
Brian Paul
parent
dfada459aa
commit
46b8fe00c9
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@ -22,6 +22,7 @@ PROGS = \
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noise \
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points \
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pointcoord \
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samplers \
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skinning \
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texdemo1 \
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toyball \
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@ -152,6 +153,13 @@ pointcoord: pointcoord.o readtex.o shaderutil.o
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$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) pointcoord.o readtex.o shaderutil.o $(LIBS) -o $@
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samplers.o: samplers.c readtex.h extfuncs.h shaderutil.h
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$(CC) -c -I$(INCDIR) $(CFLAGS) samplers.c
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samplers: samplers.o readtex.o shaderutil.o
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$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) samplers.o readtex.o shaderutil.o $(LIBS) -o $@
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skinning.o: skinning.c readtex.h extfuncs.h shaderutil.h
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$(CC) -c -I$(INCDIR) $(CFLAGS) skinning.c
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@ -0,0 +1,357 @@
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/**
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* Exercise all available GLSL texture samplers.
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*
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* Copyright (C) 2009 VMware, Inc. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/**
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* We generate a fragment shader which uses the maximum number of supported
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* texture samplers.
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* For each sampler we create a separate texture. Each texture has a
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* single strip of color at a different intensity. The fragment shader
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* samples all the textures at the same coordinate and sums the values.
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* The result should be a quad with rows of colors of increasing intensity
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* from bottom to top.
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*
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* Brian Paul
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* 1 Jan 2009
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*/
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#include <assert.h>
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "GL/glut.h"
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#include "readtex.h"
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#include "extfuncs.h"
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#include "shaderutil.h"
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#define MAX_SAMPLERS 128
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static const char *Demo = "samplers";
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static GLuint Program;
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static GLint NumSamplers;
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static GLuint Textures[MAX_SAMPLERS];
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static GLfloat Xrot = 0.0, Yrot = .0, Zrot = 0.0;
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static GLfloat EyeDist = 10;
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static GLboolean Anim = GL_FALSE;
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static void
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DrawPolygon(GLfloat size)
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{
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glPushMatrix();
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glNormal3f(0, 0, 1);
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glBegin(GL_POLYGON);
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glMultiTexCoord2f(GL_TEXTURE0, 0, 0);
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glVertex2f(-size, -size);
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glMultiTexCoord2f(GL_TEXTURE0, 1, 0);
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glVertex2f( size, -size);
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glMultiTexCoord2f(GL_TEXTURE0, 1, 1);
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glVertex2f( size, size);
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glMultiTexCoord2f(GL_TEXTURE0, 0, 1);
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glVertex2f(-size, size);
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glEnd();
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glPopMatrix();
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}
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static void
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draw(void)
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glPushMatrix();
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glTranslatef(0.0, 0.0, -EyeDist);
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glRotatef(Zrot, 0, 0, 1);
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glRotatef(Yrot, 0, 1, 0);
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glRotatef(Xrot, 1, 0, 0);
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DrawPolygon(3.0);
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glPopMatrix();
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glutSwapBuffers();
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}
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static void
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idle(void)
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{
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GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
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Yrot = t;
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glutPostRedisplay();
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}
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static void
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key(unsigned char k, int x, int y)
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{
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(void) x;
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(void) y;
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switch (k) {
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case ' ':
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case 'a':
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Anim = !Anim;
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if (Anim)
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glutIdleFunc(idle);
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else
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glutIdleFunc(NULL);
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break;
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case 'z':
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EyeDist -= 0.5;
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if (EyeDist < 3.0)
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EyeDist = 3.0;
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break;
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case 'Z':
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EyeDist += 0.5;
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if (EyeDist > 90.0)
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EyeDist = 90;
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break;
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case 27:
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exit(0);
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}
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glutPostRedisplay();
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}
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static void
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specialkey(int key, int x, int y)
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{
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GLfloat step = 2.0;
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(void) x;
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(void) y;
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switch (key) {
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case GLUT_KEY_UP:
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Xrot += step;
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break;
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case GLUT_KEY_DOWN:
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Xrot -= step;
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break;
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case GLUT_KEY_LEFT:
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Yrot -= step;
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break;
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case GLUT_KEY_RIGHT:
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Yrot += step;
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break;
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}
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glutPostRedisplay();
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}
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/* new window size or exposure */
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static void
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Reshape(int width, int height)
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{
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GLfloat ar = (float) width / (float) height;
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glViewport(0, 0, (GLint)width, (GLint)height);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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}
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static void
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InitTextures(void)
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{
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const GLint size = MAX_SAMPLERS;
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GLubyte *texImage;
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GLenum filter = GL_NEAREST;
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GLint stripeSize;
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GLint s;
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texImage = (GLubyte *) malloc(size * size * 4);
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glGenTextures(NumSamplers, Textures);
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/* size of texels stripe */
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stripeSize = size / NumSamplers;
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/* create a texture for each sampler */
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for (s = 0; s < NumSamplers; s++) {
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GLint x, y, ypos;
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GLubyte intensity = 31 + s * (256-32) / (NumSamplers - 1);
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printf("Texture %d: color = %d, %d, %d\n", s,
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(int) intensity, 0, (int) intensity );
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/* initialize the texture to black */
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memset(texImage, 0, size * size * 4);
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/* set a stripe of texels to the intensity value */
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ypos = s * stripeSize;
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for (y = 0; y < stripeSize; y++) {
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for (x = 0; x < size; x++) {
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GLint k = 4 * ((ypos + y) * size + x);
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texImage[k + 0] = intensity;
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texImage[k + 1] = intensity;
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texImage[k + 2] = 0;
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texImage[k + 3] = 255;
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}
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}
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glActiveTexture(GL_TEXTURE0 + s);
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glBindTexture(GL_TEXTURE_2D, Textures[s]);
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gluBuild2DMipmaps(GL_TEXTURE_2D, 4, size, size,
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GL_RGBA, GL_UNSIGNED_BYTE, texImage);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
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}
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free(texImage);
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}
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/**
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* Generate a fragment shader that uses the given number of samplers.
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*/
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static char *
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GenFragmentShader(GLint numSamplers)
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{
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const int maxLen = 10 * 1000;
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char *prog = (char *) malloc(maxLen);
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char *p = prog;
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int s;
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p += sprintf(p, "// Generated fragment shader:\n");
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for (s = 0; s < numSamplers; s++) {
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p += sprintf(p, "uniform sampler2D tex%d;\n", s);
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}
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p += sprintf(p, "void main()\n");
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p += sprintf(p, "{\n");
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p += sprintf(p, " vec4 color = vec4(0.0);\n");
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for (s = 0; s < numSamplers; s++) {
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p += sprintf(p, " color += texture2D(tex%d, gl_TexCoord[0].xy);\n", s);
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}
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p += sprintf(p, " gl_FragColor = color;\n");
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p += sprintf(p, "}\n");
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assert(p - prog < maxLen);
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return prog;
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}
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/** Create & bind shader program */
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static GLuint
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CreateProgram(void)
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{
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GLuint fragShader, vertShader, program;
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const char *vertShaderText =
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"void main() \n"
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"{ \n"
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" gl_TexCoord[0] = gl_MultiTexCoord0; \n"
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" gl_Position = ftransform(); \n"
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"} \n";
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char *fragShaderText = GenFragmentShader(NumSamplers);
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printf("%s", fragShaderText);
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vertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
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fragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
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assert(vertShader);
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program = LinkShaders(vertShader, fragShader);
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glUseProgram_func(program);
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free(fragShaderText);
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return program;
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}
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static void
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InitProgram(void)
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{
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GLint s;
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Program = CreateProgram();
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/* init sampler uniforms */
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for (s = 0; s < NumSamplers; s++) {
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char uname[10];
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GLint loc;
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sprintf(uname, "tex%d", s);
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loc = glGetUniformLocation_func(Program, uname);
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assert(loc >= 0);
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glUniform1i_func(loc, s);
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}
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}
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static void
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InitGL(void)
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{
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if (!ShadersSupported()) {
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printf("GLSL not supported!\n");
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exit(1);
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}
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printf("GL_RENDERER = %s\n", (const char *) glGetString(GL_RENDERER));
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GetExtensionFuncs();
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glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &NumSamplers);
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if (NumSamplers > MAX_SAMPLERS)
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NumSamplers = MAX_SAMPLERS;
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printf("Testing %d samplers\n", NumSamplers);
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InitTextures();
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InitProgram();
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glClearColor(.6, .6, .9, 0);
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glColor3f(1.0, 1.0, 1.0);
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printf("Each color corresponds to a separate sampler/texture.\n");
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}
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int
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main(int argc, char *argv[])
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{
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glutInit(&argc, argv);
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glutInitWindowSize(500, 400);
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glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
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glutCreateWindow(Demo);
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glutReshapeFunc(Reshape);
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glutKeyboardFunc(key);
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glutSpecialFunc(specialkey);
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glutDisplayFunc(draw);
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if (Anim)
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glutIdleFunc(idle);
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InitGL();
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glutMainLoop();
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return 0;
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}
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