progs/tests/floattex.c

   1 /*
   2  * Test floating point textures.
   3  */
   4
   5
   6 #include <assert.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <math.h>
  10 #include <GL/glew.h>
  11 #include <GL/glut.h>
  12 #include "extfuncs.h"
  13 #include "readtex.h"
  14 #include "shaderutil.h"
  15
  16
  17 static const char *TexFile = "../images/arch.rgb";
  18
  19 static const char *FragShaderText =
  20    "uniform sampler2D tex1; \n"
  21    "void main() \n"
  22    "{ \n"
  23    "   vec4 t = texture2D(tex1, gl_TexCoord[0].xy); \n"
  24    "   // convert from [-255,0] to [0,1] \n"
  25    "   gl_FragColor = t * (-1.0 / 255.0); \n"
  26    "} \n";
  27
  28 static const char *VertShaderText =
  29    "void main() \n"
  30    "{ \n"
  31    "   gl_TexCoord[0] = gl_MultiTexCoord0; \n"
  32    "   gl_Position = ftransform(); \n"
  33    "} \n";
  34
  35 static struct uniform_info Uniforms[] = {
  36    { "tex1",  1, GL_SAMPLER_2D, { 0, 0, 0, 0 }, -1 },
  37    END_OF_UNIFORMS
  38 };
  39
  40
  41 static GLuint Program;
  42
  43
  44
  45 static GLboolean
  46 CheckError( int line )
  47 {
  48    GLenum error = glGetError();
  49    if (error) {
  50       char *err = (char *) gluErrorString( error );
  51       fprintf( stderr, "GL Error: %s at line %d\n", err, line );
  52       return GL_TRUE;
  53    }
  54    return GL_FALSE;
  55 }
  56
  57
  58 static void
  59 Draw(void)
  60 {
  61    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  62
  63    glPushMatrix();
  64
  65    glBegin(GL_POLYGON);
  66    glTexCoord2f( 0.0, 0.0 );   glVertex2f( -1.0, -1.0 );
  67    glTexCoord2f( 1.0, 0.0 );   glVertex2f(  1.0, -1.0 );
  68    glTexCoord2f( 1.0, 1.0 );   glVertex2f(  1.0,  1.0 );
  69    glTexCoord2f( 0.0, 1.0 );   glVertex2f( -1.0,  1.0 );
  70    glEnd();
  71
  72    glPopMatrix();
  73
  74    glutSwapBuffers();
  75 }
  76
  77
  78 static void
  79 Reshape(int width, int height)
  80 {
  81    glViewport(0, 0, width, height);
  82    glMatrixMode(GL_PROJECTION);
  83    glLoadIdentity();
  84    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  85    glMatrixMode(GL_MODELVIEW);
  86    glLoadIdentity();
  87    glTranslatef(0.0, 0.0, -8.0);
  88 }
  89
  90
  91 static void
  92 Key(unsigned char key, int x, int y)
  93 {
  94    (void) x;
  95    (void) y;
  96    switch (key) {
  97       case 27:
  98          exit(0);
  99          break;
 100    }
 101    glutPostRedisplay();
 102 }
 103
 104
 105 static void
 106 InitTexture(void)
 107 {
 108    GLenum filter = GL_LINEAR;
 109    GLint imgWidth, imgHeight;
 110    GLenum imgFormat;
 111    GLubyte *image = NULL;
 112    GLfloat *ftex;
 113    GLint i, t;
 114
 115    image = LoadRGBImage(TexFile, &imgWidth, &imgHeight, &imgFormat);
 116    if (!image) {
 117       printf("Couldn't read %s\n", TexFile);
 118       exit(0);
 119    }
 120
 121    assert(imgFormat == GL_RGB);
 122
 123    ftex = (float *) malloc(imgWidth * imgHeight * 4 * sizeof(float));
 124    if (!ftex) {
 125       printf("out of memory\n");
 126       exit(0);
 127    }
 128
 129    /* convert ubytes to floats, negated */
 130    for (i = 0; i < imgWidth * imgHeight * 3; i++) {
 131       ftex[i] = -1.0f * image[i];
 132    }
 133
 134    glActiveTexture(GL_TEXTURE0);
 135    glBindTexture(GL_TEXTURE_2D, 42);
 136
 137    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB,
 138                 imgWidth, imgHeight, 0,
 139                 GL_RGB, GL_FLOAT, ftex);
 140
 141
 142    CheckError(__LINE__);
 143
 144    /* sanity checks */
 145    glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_RED_TYPE_ARB, &t);
 146    assert(t == GL_FLOAT);
 147    glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_GREEN_TYPE_ARB, &t);
 148    assert(t == GL_FLOAT);
 149    glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_BLUE_TYPE_ARB, &t);
 150    assert(t == GL_FLOAT);
 151    glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_TYPE_ARB, &t);
 152    assert(t == GL_FLOAT);
 153
 154    free(image);
 155    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 156    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 157    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
 158    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
 159
 160    if (1) {
 161       /* read back the texture and make sure values are correct */
 162       GLfloat *tex2 = (GLfloat *)
 163          malloc(imgWidth * imgHeight * 4 * sizeof(GLfloat));
 164       glGetTexImage(GL_TEXTURE_2D, 0, imgFormat, GL_FLOAT, tex2);
 165       CheckError(__LINE__);
 166       for (i = 0; i < imgWidth * imgHeight * 4; i++) {
 167          if (ftex[i] != tex2[i]) {
 168             printf("tex[%d] %g != tex2[%d] %g\n",
 169                    i, ftex[i], i, tex2[i]);
 170          }
 171       }
 172    }
 173
 174    free(ftex);
 175 }
 176
 177
 178 static GLuint
 179 CreateProgram(void)
 180 {
 181    GLuint fragShader, vertShader, program;
 182
 183    vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
 184    fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
 185    assert(vertShader);
 186    program = LinkShaders(vertShader, fragShader);
 187
 188    assert(program);
 189
 190    glUseProgram_func(program);
 191
 192    SetUniformValues(program, Uniforms);
 193
 194    return program;
 195 }
 196
 197
 198 static void
 199 Init(void)
 200 {
 201    glClearColor(0.25, 0.25, 0.25, 0.0);
 202
 203    GetExtensionFuncs();
 204
 205    if (!ShadersSupported()) {
 206       printf("Sorry, this test requires GLSL\n");
 207       exit(1);
 208    }
 209
 210    if (!glutExtensionSupported("GL_MESAX_texture_float") &&
 211        !glutExtensionSupported("GL_ARB_texture_float")) {
 212       printf("Sorry, this test requires GL_MESAX/ARB_texture_float\n");
 213       exit(1);
 214    }
 215
 216    InitTexture();
 217
 218    Program = CreateProgram();
 219    glUseProgram_func(Program);
 220 }
 221
 222
 223 int
 224 main(int argc, char *argv[])
 225 {
 226    glutInit(&argc, argv);
 227    glutInitWindowPosition(0, 0);
 228    glutInitWindowSize(400, 400);
 229    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 230    glutCreateWindow(argv[0]);
 231    glewInit();
 232    glutReshapeFunc(Reshape);
 233    glutKeyboardFunc(Key);
 234    glutDisplayFunc(Draw);
 235    Init();
 236    glutMainLoop();
 237    return 0;
 238 }