src/tests/viewmemory.c

   1 /**
   2  * Try to see other parts of the user's video memory by creating textures
   3  * with uninitialized contents.  Display those textures in the window.
   4  * Insprired by stories of WebGL security issues.
   5  *
   6  * The OpenGL driver should probably initialize all memory allocations
   7  * to zero (textures, renderbuffers, buffer objects, etc).
   8  *
   9  * Brian Paul
  10  * June 2011
  11  */
  12
  13 #define GL_GLEXT_PROTOTYPES
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <math.h>
  18 #include <GL/glew.h>
  19 #include "glut_wrap.h"
  20
  21 static int Win;
  22 static int WinWidth = 1024, WinHeight = 512;
  23 static GLboolean Anim = GL_FALSE;
  24
  25 static GLuint *Textures;
  26 static GLuint TexWidth = 1024, TexHeight = 512;
  27 static GLuint NumTextures = 50, CurTexture;
  28
  29
  30 static void
  31 Idle(void)
  32 {
  33    static int prevTime = 0;
  34    int curTime = glutGet(GLUT_ELAPSED_TIME);
  35
  36    if (!prevTime) {
  37       prevTime = curTime;
  38    }
  39    else {
  40       if (curTime - prevTime > 250) {
  41          prevTime = curTime;
  42          CurTexture = (CurTexture + 1) % NumTextures;
  43          glutPostRedisplay();
  44       }
  45    }
  46 }
  47
  48
  49 static void
  50 MakeTextures(void)
  51 {
  52    GLuint i;
  53
  54    Textures = (GLuint *) malloc(NumTextures * sizeof(GLuint));
  55
  56    glGenTextures(NumTextures, Textures);
  57    for (i = 0; i < NumTextures; i++) {
  58       glBindTexture(GL_TEXTURE_2D, Textures[i]);
  59       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  60       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  61       glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TexWidth, TexHeight, 0,
  62                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
  63    }
  64 }
  65
  66
  67 static void
  68 PrintString(const char *s)
  69 {
  70    while (*s) {
  71       glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
  72       s++;
  73    }
  74 }
  75
  76
  77 static void
  78 Draw(void)
  79 {
  80    char s[100];
  81
  82    sprintf(s, "Texture %u", CurTexture);
  83
  84    glClear(GL_COLOR_BUFFER_BIT);
  85
  86    glEnable(GL_TEXTURE_2D);
  87    glBindTexture(GL_TEXTURE_2D, CurTexture);
  88
  89    glBegin(GL_POLYGON);
  90    glTexCoord2f(0, 0);  glVertex2f(0, 0);
  91    glTexCoord2f(1, 0);  glVertex2f(WinWidth, 0);
  92    glTexCoord2f(1, 1);  glVertex2f(WinWidth, WinHeight);
  93    glTexCoord2f(0, 1);  glVertex2f(0, WinHeight);
  94    glEnd();
  95
  96    glDisable(GL_TEXTURE_2D);
  97    glColor3f(0, 1, 0);
  98    glWindowPos2iARB(10, 10);
  99    PrintString(s);
 100
 101    glutSwapBuffers();
 102 }
 103
 104
 105 static void
 106 Reshape(int width, int height)
 107 {
 108    WinWidth = width;
 109    WinHeight = height;
 110    glViewport(0, 0, width, height);
 111    glMatrixMode(GL_PROJECTION);
 112    glLoadIdentity();
 113    glOrtho(0, WinWidth, 0, WinHeight, -1, 1);
 114    glMatrixMode(GL_MODELVIEW);
 115    glLoadIdentity();
 116 }
 117
 118
 119 static void
 120 Key(unsigned char key, int x, int y)
 121 {
 122    switch (key) {
 123    case 'a':
 124    case 'A':
 125       Anim = !Anim;
 126       if (Anim)
 127          glutIdleFunc(Idle);
 128       else
 129          glutIdleFunc(NULL);
 130       break;
 131    case 27:
 132       glutDestroyWindow(Win);
 133       exit(0);
 134       break;
 135    }
 136    glutPostRedisplay();
 137 }
 138
 139
 140 static void
 141 SpecialKey(int key, int x, int y)
 142 {
 143    (void) x;
 144    (void) y;
 145    switch (key) {
 146    case GLUT_KEY_LEFT:
 147       if (CurTexture > 0)
 148          CurTexture--;
 149       break;
 150    case GLUT_KEY_RIGHT:
 151       if (CurTexture + 1 < NumTextures)
 152          CurTexture++;
 153       break;
 154    }
 155    glutPostRedisplay();
 156 }
 157
 158
 159 static void
 160 Init(void)
 161 {
 162    printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER));
 163    if (glutExtensionSupported("GL_ARB_robustness"))
 164       printf("GL_ARB_robustness supported\n");
 165    else
 166       printf("GL_ARB_robustness not supported\n");
 167
 168    MakeTextures();
 169    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 170
 171    printf("Keys:\n");
 172    printf("  a: toggle animation\n");
 173    printf("  Left/Right: back / next frame\n");
 174    printf("  Esc: exit\n");
 175 }
 176
 177
 178 int
 179 main(int argc, char *argv[])
 180 {
 181    glutInit(&argc, argv);
 182
 183    if (argc > 1) {
 184       NumTextures = atoi(argv[1]);
 185       if (NumTextures < 1) {
 186          printf("Invalid argument (number of textures)\n");
 187          return 1;
 188       }
 189    }
 190    printf("Creating %u textures\n", NumTextures);
 191
 192    glutInitWindowSize(WinWidth, WinHeight);
 193    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
 194    Win = glutCreateWindow(argv[0]);
 195    glewInit();
 196    glutReshapeFunc(Reshape);
 197    glutKeyboardFunc(Key);
 198    glutSpecialFunc(SpecialKey);
 199    glutDisplayFunc(Draw);
 200
 201    if (Anim)
 202       glutIdleFunc(Idle);
 203
 204    Init();
 205
 206    glutMainLoop();
 207    return 0;
 208 }