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/*
* Test floating point textures.
* No actual rendering, yet.
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glew.h>
#include <GL/glut.h>
#include "extfuncs.h"
#include "readtex.h"
#include "shaderutil.h"
static const char *TexFile = "../images/arch.rgb";
static const char *FragShaderText =
"uniform sampler2D tex1; \n"
"void main() \n"
"{ \n"
" vec4 t = texture2D(tex1, gl_TexCoord[0].xy); \n"
" // convert from [-255,0] to [0,1] \n"
" gl_FragColor = t * (-1.0 / 255.0); \n"
"} \n";
static const char *VertShaderText =
"void main() \n"
"{ \n"
" gl_TexCoord[0] = gl_MultiTexCoord0; \n"
" gl_Position = ftransform(); \n"
"} \n";
static struct uniform_info Uniforms[] = {
{ "tex1", 1, GL_INT, { 0, 0, 0, 0 }, -1 },
END_OF_UNIFORMS
};
static GLuint Program;
static GLboolean
CheckError( int line )
{
GLenum error = glGetError();
if (error) {
char *err = (char *) gluErrorString( error );
fprintf( stderr, "GL Error: %s at line %d\n", err, line );
return GL_TRUE;
}
return GL_FALSE;
}
static void
Draw(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glBegin(GL_POLYGON);
glTexCoord2f( 0.0, 0.0 ); glVertex2f( -1.0, -1.0 );
glTexCoord2f( 1.0, 0.0 ); glVertex2f( 1.0, -1.0 );
glTexCoord2f( 1.0, 1.0 ); glVertex2f( 1.0, 1.0 );
glTexCoord2f( 0.0, 1.0 ); glVertex2f( -1.0, 1.0 );
glEnd();
glPopMatrix();
glutSwapBuffers();
}
static void
Reshape(int width, int height)
{
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -8.0);
}
static void
Key(unsigned char key, int x, int y)
{
(void) x;
(void) y;
switch (key) {
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void
InitTexture(void)
{
GLenum filter = GL_LINEAR;
GLint imgWidth, imgHeight;
GLenum imgFormat;
GLubyte *image = NULL;
GLfloat *ftex;
GLint i, t;
image = LoadRGBImage(TexFile, &imgWidth, &imgHeight, &imgFormat);
if (!image) {
printf("Couldn't read %s\n", TexFile);
exit(0);
}
assert(imgFormat == GL_RGB);
ftex = (float *) malloc(imgWidth * imgHeight * 4 * sizeof(float));
if (!ftex) {
printf("out of memory\n");
exit(0);
}
/* convert ubytes to floats, negated */
for (i = 0; i < imgWidth * imgHeight * 3; i++) {
ftex[i] = -1.0f * image[i];
}
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, 42);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB,
imgWidth, imgHeight, 0,
GL_RGB, GL_FLOAT, ftex);
/* sanity checks */
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_RED_TYPE_ARB, &t);
assert(t == GL_FLOAT);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_GREEN_TYPE_ARB, &t);
assert(t == GL_FLOAT);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_BLUE_TYPE_ARB, &t);
assert(t == GL_FLOAT);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_TYPE_ARB, &t);
assert(t == GL_FLOAT);
free(image);
free(ftex);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
#if 0
/* read back the texture and make sure values are correct */
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_FLOAT, tex2);
CheckError(__LINE__);
for (i = 0; i < 16; i++) {
for (j = 0; j < 16; j++) {
if (tex[i][j][0] != tex2[i][j][0] ||
tex[i][j][1] != tex2[i][j][1] ||
tex[i][j][2] != tex2[i][j][2] ||
tex[i][j][3] != tex2[i][j][3]) {
printf("tex[%d][%d] %g %g %g %g != tex2[%d][%d] %g %g %g %g\n",
i, j,
tex[i][j][0], tex[i][j][1], tex[i][j][2], tex[i][j][3],
i, j,
tex2[i][j][0], tex2[i][j][1], tex2[i][j][2], tex2[i][j][3]);
}
}
}
#endif
}
static GLuint
CreateProgram(void)
{
GLuint fragShader, vertShader, program;
vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
assert(vertShader);
program = LinkShaders(vertShader, fragShader);
assert(program);
// InitUniforms(program, Uniforms);
return program;
}
static void
Init(void)
{
glClearColor(0.25, 0.25, 0.25, 0.0);
GetExtensionFuncs();
if (!ShadersSupported()) {
printf("Sorry, this test requires GLSL\n");
exit(1);
}
if (!glutExtensionSupported("GL_MESAX_texture_float")) {
printf("Sorry, this test requires GL_MESAX_texture_float\n");
exit(1);
}
InitTexture();
Program = CreateProgram();
glUseProgram_func(Program);
}
int
main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitWindowPosition(0, 0);
glutInitWindowSize(400, 400);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutCreateWindow(argv[0]);
glewInit();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutDisplayFunc(Draw);
Init();
glutMainLoop();
return 0;
}
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