progs/tests/floattex.c

   1 /*
   2  * Test floating point textures.
   3  * No actual rendering, yet.
   4  */
   5
   6
   7 #include <assert.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <math.h>
  11 #include <GL/glew.h>
  12 #include <GL/glut.h>
  13 #include "extfuncs.h"
  14 #include "readtex.h"
  15 #include "shaderutil.h"
  16
  17
  18 static const char *TexFile = "../images/arch.rgb";
  19
  20 static const char *FragShaderText =
  21    "uniform sampler2D tex1; \n"
  22    "void main() \n"
  23    "{ \n"
  24    "   vec4 t = texture2D(tex1, gl_TexCoord[0].xy); \n"
  25    "   // convert from [-255,0] to [0,1] \n"
  26    "   gl_FragColor = t * (-1.0 / 255.0); \n"
  27    "} \n";
  28
  29 static const char *VertShaderText =
  30    "void main() \n"
  31    "{ \n"
  32    "   gl_TexCoord[0] = gl_MultiTexCoord0; \n"
  33    "   gl_Position = ftransform(); \n"
  34    "} \n";
  35
  36 static struct uniform_info Uniforms[] = {
  37    { "tex1",  1, GL_INT, { 0, 0, 0, 0 }, -1 },
  38    END_OF_UNIFORMS
  39 };
  40
  41
  42 static GLuint Program;
  43
  44
  45
  46 static GLboolean
  47 CheckError( int line )
  48 {
  49    GLenum error = glGetError();
  50    if (error) {
  51       char *err = (char *) gluErrorString( error );
  52       fprintf( stderr, "GL Error: %s at line %d\n", err, line );
  53       return GL_TRUE;
  54    }
  55    return GL_FALSE;
  56 }
  57
  58
  59 static void
  60 Draw(void)
  61 {
  62    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  63
  64    glPushMatrix();
  65
  66    glBegin(GL_POLYGON);
  67    glTexCoord2f( 0.0, 0.0 );   glVertex2f( -1.0, -1.0 );
  68    glTexCoord2f( 1.0, 0.0 );   glVertex2f(  1.0, -1.0 );
  69    glTexCoord2f( 1.0, 1.0 );   glVertex2f(  1.0,  1.0 );
  70    glTexCoord2f( 0.0, 1.0 );   glVertex2f( -1.0,  1.0 );
  71    glEnd();
  72
  73    glPopMatrix();
  74
  75    glutSwapBuffers();
  76 }
  77
  78
  79 static void
  80 Reshape(int width, int height)
  81 {
  82    glViewport(0, 0, width, height);
  83    glMatrixMode(GL_PROJECTION);
  84    glLoadIdentity();
  85    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  86    glMatrixMode(GL_MODELVIEW);
  87    glLoadIdentity();
  88    glTranslatef(0.0, 0.0, -8.0);
  89 }
  90
  91
  92 static void
  93 Key(unsigned char key, int x, int y)
  94 {
  95    (void) x;
  96    (void) y;
  97    switch (key) {
  98       case 27:
  99          exit(0);
 100          break;
 101    }
 102    glutPostRedisplay();
 103 }
 104
 105
 106
 107 static void
 108 InitTexture(void)
 109 {
 110    GLenum filter = GL_LINEAR;
 111    GLint imgWidth, imgHeight;
 112    GLenum imgFormat;
 113    GLubyte *image = NULL;
 114    GLfloat *ftex;
 115    GLint i, t;
 116
 117    image = LoadRGBImage(TexFile, &imgWidth, &imgHeight, &imgFormat);
 118    if (!image) {
 119       printf("Couldn't read %s\n", TexFile);
 120       exit(0);
 121    }
 122
 123    assert(imgFormat == GL_RGB);
 124
 125    ftex = (float *) malloc(imgWidth * imgHeight * 4 * sizeof(float));
 126    if (!ftex) {
 127       printf("out of memory\n");
 128       exit(0);
 129    }
 130
 131    /* convert ubytes to floats, negated */
 132    for (i = 0; i < imgWidth * imgHeight * 3; i++) {
 133       ftex[i] = -1.0f * image[i];
 134    }
 135
 136    glActiveTexture(GL_TEXTURE0);
 137    glBindTexture(GL_TEXTURE_2D, 42);
 138
 139    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB,
 140                 imgWidth, imgHeight, 0,
 141                 GL_RGB, GL_FLOAT, ftex);
 142
 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    free(ftex);
 156
 157    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 158    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 159    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
 160    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
 161
 162 #if 0
 163    /* read back the texture and make sure values are correct */
 164    glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_FLOAT, tex2);
 165    CheckError(__LINE__);
 166    for (i = 0; i < 16; i++) {
 167       for (j = 0; j < 16; j++) {
 168          if (tex[i][j][0] != tex2[i][j][0] ||
 169              tex[i][j][1] != tex2[i][j][1] ||
 170              tex[i][j][2] != tex2[i][j][2] ||
 171              tex[i][j][3] != tex2[i][j][3]) {
 172             printf("tex[%d][%d] %g %g %g %g != tex2[%d][%d] %g %g %g %g\n",
 173                    i, j,
 174                    tex[i][j][0], tex[i][j][1], tex[i][j][2], tex[i][j][3],
 175                    i, j,
 176                    tex2[i][j][0], tex2[i][j][1], tex2[i][j][2], tex2[i][j][3]);
 177          }
 178       }
 179    }
 180 #endif
 181 }
 182
 183
 184 static GLuint
 185 CreateProgram(void)
 186 {
 187    GLuint fragShader, vertShader, program;
 188
 189    vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
 190    fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
 191    assert(vertShader);
 192    program = LinkShaders(vertShader, fragShader);
 193
 194    assert(program);
 195
 196    // InitUniforms(program, Uniforms);
 197
 198    return program;
 199 }
 200
 201
 202 static void
 203 Init(void)
 204 {
 205    glClearColor(0.25, 0.25, 0.25, 0.0);
 206
 207    GetExtensionFuncs();
 208
 209    if (!ShadersSupported()) {
 210       printf("Sorry, this test requires GLSL\n");
 211       exit(1);
 212    }
 213
 214    if (!glutExtensionSupported("GL_MESAX_texture_float")) {
 215       printf("Sorry, this test requires GL_MESAX_texture_float\n");
 216       exit(1);
 217    }
 218
 219    InitTexture();
 220
 221    Program = CreateProgram();
 222    glUseProgram_func(Program);
 223 }
 224
 225
 226 int
 227 main(int argc, char *argv[])
 228 {
 229    glutInit(&argc, argv);
 230    glutInitWindowPosition(0, 0);
 231    glutInitWindowSize(400, 400);
 232    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 233    glutCreateWindow(argv[0]);
 234    glewInit();
 235    glutReshapeFunc(Reshape);
 236    glutKeyboardFunc(Key);
 237    glutDisplayFunc(Draw);
 238    Init();
 239    glutMainLoop();
 240    return 0;
 241 }