| Brian | ca2f2c7 | 2008-02-14 14:54:37 -0700 | [diff] [blame] | 1 | /** |
| 2 | * Test glPolygonMode. |
| 3 | * A tri-strip w/ two tris is drawn so that the first tri is front-facing |
| 4 | * but the second tri is back-facing. |
| 5 | * Set glPolygonMode differently for the front/back faces |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | |
| 10 | #include <stdio.h> |
| 11 | #include <stdlib.h> |
| 12 | #include <math.h> |
| 13 | #include <GL/glut.h> |
| 14 | |
| 15 | static int Win; |
| 16 | static GLfloat Zrot = 0; |
| 17 | static GLboolean FrontFillBackUnfilled = GL_TRUE; |
| 18 | static GLboolean Lines = GL_TRUE; |
| 19 | |
| 20 | |
| 21 | static void |
| 22 | Draw(void) |
| 23 | { |
| 24 | glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); |
| 25 | |
| 26 | if (FrontFillBackUnfilled) { |
| 27 | if (Lines) { |
| 28 | printf("FrontMode = FILL, BackMode = LINE\n"); |
| 29 | glPolygonMode(GL_BACK, GL_LINE); |
| 30 | } |
| 31 | else { |
| 32 | printf("FrontMode = FILL, BackMode = POINT\n"); |
| 33 | glPolygonMode(GL_BACK, GL_POINT); |
| 34 | } |
| 35 | glPolygonMode(GL_FRONT, GL_FILL); |
| 36 | } |
| 37 | else { |
| 38 | if (Lines) { |
| 39 | printf("FrontMode = LINE, BackMode = FILL\n"); |
| 40 | glPolygonMode(GL_FRONT, GL_LINE); |
| 41 | } |
| 42 | else { |
| 43 | printf("FrontMode = POINT, BackMode = FILL\n"); |
| 44 | glPolygonMode(GL_FRONT, GL_POINT); |
| 45 | } |
| 46 | glPolygonMode(GL_BACK, GL_FILL); |
| 47 | } |
| 48 | |
| 49 | glPushMatrix(); |
| 50 | glRotatef(Zrot, 0, 0, 1); |
| 51 | |
| 52 | glBegin(GL_TRIANGLE_STRIP); |
| 53 | glVertex2f(-1, 0); |
| 54 | glVertex2f( 1, 0); |
| 55 | glVertex2f(0, 1); |
| 56 | glVertex2f(0, -1); |
| 57 | glEnd(); |
| 58 | |
| 59 | glPopMatrix(); |
| 60 | |
| 61 | glutSwapBuffers(); |
| 62 | } |
| 63 | |
| 64 | |
| 65 | static void |
| 66 | Reshape(int width, int height) |
| 67 | { |
| 68 | glViewport(0, 0, width, height); |
| 69 | glMatrixMode(GL_PROJECTION); |
| 70 | glLoadIdentity(); |
| 71 | glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); |
| 72 | glMatrixMode(GL_MODELVIEW); |
| 73 | glLoadIdentity(); |
| 74 | glTranslatef(0.0, 0.0, -15.0); |
| 75 | } |
| 76 | |
| 77 | |
| 78 | static void |
| 79 | Key(unsigned char key, int x, int y) |
| 80 | { |
| 81 | const GLfloat step = 3.0; |
| 82 | (void) x; |
| 83 | (void) y; |
| 84 | switch (key) { |
| 85 | case 'p': |
| 86 | FrontFillBackUnfilled = !FrontFillBackUnfilled; |
| 87 | break; |
| 88 | case 'l': |
| 89 | Lines = !Lines; |
| 90 | break; |
| 91 | case 'z': |
| 92 | Zrot -= step; |
| 93 | break; |
| 94 | case 'Z': |
| 95 | Zrot += step; |
| 96 | break; |
| 97 | case 27: |
| 98 | glutDestroyWindow(Win); |
| 99 | exit(0); |
| 100 | break; |
| 101 | } |
| 102 | glutPostRedisplay(); |
| 103 | } |
| 104 | |
| 105 | |
| 106 | static void |
| 107 | Init(void) |
| 108 | { |
| 109 | printf("GL_RENDERER = %s\n", (char*) glGetString(GL_RENDERER)); |
| 110 | |
| 111 | glLineWidth(3.0); |
| 112 | glPointSize(3.0); |
| 113 | |
| 114 | glColor4f(1, 1, 1, 0.8); |
| 115 | glEnable(GL_BLEND); |
| 116 | glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); |
| 117 | |
| 118 | printf("Press 'p' to toggle polygon mode\n"); |
| 119 | } |
| 120 | |
| 121 | |
| 122 | int |
| 123 | main(int argc, char *argv[]) |
| 124 | { |
| 125 | glutInit(&argc, argv); |
| 126 | glutInitWindowPosition(0, 0); |
| 127 | glutInitWindowSize(400, 400); |
| 128 | glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); |
| 129 | Win = glutCreateWindow(argv[0]); |
| 130 | glutReshapeFunc(Reshape); |
| 131 | glutKeyboardFunc(Key); |
| 132 | glutDisplayFunc(Draw); |
| 133 | Init(); |
| 134 | glutMainLoop(); |
| 135 | return 0; |
| 136 | } |