/* * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc. * * Permission to use, copy, modify, distribute, and sell this software and * its documentation for any purpose is hereby granted without fee, provided * that (i) the above copyright notices and this permission notice appear in * all copies of the software and related documentation, and (ii) the name of * Silicon Graphics may not be used in any advertising or * publicity relating to the software without the specific, prior written * permission of Silicon Graphics. * * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF * ANY KIND, * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. * * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. */ #include #include #include #include GLenum doubleBuffer = 1; int win; static float tx = 0; static float ty = 0; static float tw = 0; static float th = 0; static float z = -5; static float win_width = 250; static float win_height = 250; static enum { ORTHO, FRUSTUM, MODE_MAX } mode = ORTHO; static void Init(void) { fprintf(stderr, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); fprintf(stderr, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION)); fprintf(stderr, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR)); fflush(stderr); glClearColor(0, 0, 0, 0.0); } static void Reshape(int width, int height) { win_width = width; win_height = height; glutPostRedisplay(); } static void Key(unsigned char key, int x, int y) { switch (key) { case 27: exit(0); case 'w': tw += 1.0; break; case 'W': tw -= 1.0; break; case 'h': th += 1.0; break; case 'H': th -= 1.0; break; case 'z': z += 1.0; break; case 'Z': z -= 1.0; break; case 'm': mode++; mode %= MODE_MAX; break; case ' ': tw = th = tx = ty = 0; z = -5; mode = ORTHO; break; default: break; } glutPostRedisplay(); } static void Draw(void) { int i; float w = tw + win_width; float h = th + win_height; fprintf(stderr, "glViewport(%f %f %f %f)\n", tx, ty, w, h); fprintf(stderr, "mode: %s\n", mode == FRUSTUM ? "FRUSTUM" : "ORTHO"); fprintf(stderr, "z: %f\n", z); fflush(stderr); glMatrixMode(GL_PROJECTION); glLoadIdentity(); switch (mode) { case FRUSTUM: glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); break; case ORTHO: default: glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); break; } glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glClear(GL_COLOR_BUFFER_BIT); /*********************************************************************** * Should be clipped to be no larger than the triangles: */ glViewport(tx, ty, w, h); glBegin(GL_POLYGON); glColor3f(1,1,0); glVertex3f(-100, -100, z); glVertex3f(-100, 100, z); glVertex3f(100, 100, z); glVertex3f(100, -100, z); glEnd(); glBegin(GL_POLYGON); glColor3f(0,1,1); glVertex3f(-10, -10, z); glVertex3f(-10, 10, z); glVertex3f(10, 10, z); glVertex3f(10, -10, z); glEnd(); glBegin(GL_POLYGON); glColor3f(1,0,0); glVertex3f(-2, -2, z); glVertex3f(-2, 2, z); glVertex3f(2, 2, z); glVertex3f(2, -2, z); glEnd(); glBegin(GL_POLYGON); glColor3f(.5,.5,1); glVertex3f(-1, -1, z); glVertex3f(-1, 1, z); glVertex3f(1, 1, z); glVertex3f(1, -1, z); glEnd(); /*********************************************************************** */ glViewport(0, 0, win_width, win_height); glBegin(GL_LINES); glColor3f(1,1,0); glVertex3f(-1, 0, z); glVertex3f(1, 0, z); glVertex3f(0, -1, z); glVertex3f(0, 1, z); glEnd(); /*********************************************************************** */ glViewport(tx, ty, w, h); glBegin(GL_TRIANGLES); glColor3f(1,0,0); glVertex3f(-1, -1, z); glVertex3f(0, -1, z); glVertex3f(-.5, -.5, z); glColor3f(1,1,1); glVertex3f(0, -1, z); glVertex3f(1, -1, z); glVertex3f(.5, -.5, z); glVertex3f(-.5, -.5, z); glVertex3f(.5, -.5, z); glVertex3f(0, 0, z); glColor3f(0,1,0); glVertex3f(1, 1, z); glVertex3f(0, 1, z); glVertex3f(.5, .5, z); glColor3f(1,1,1); glVertex3f(0, 1, z); glVertex3f(-1, 1, z); glVertex3f(-.5, .5, z); glVertex3f(.5, .5, z); glVertex3f(-.5, .5, z); glVertex3f( 0, 0, z); glEnd(); glViewport(0, 0, win_width, win_height); glBegin(GL_LINES); glColor3f(.5,.5,0); for (i = -10; i < 10; i++) { float f = i / 10.0; if (i == 0) continue; glVertex3f(-1, f, z); glVertex3f(1, f, z); glVertex3f(f, -1, z); glVertex3f(f, 1, z); } glEnd(); glFlush(); if (doubleBuffer) { glutSwapBuffers(); } } static GLenum Args(int argc, char **argv) { GLint i; if (getenv("VPX")) tx = atof(getenv("VPX")); if (getenv("VPY")) ty = atof(getenv("VPY")); for (i = 1; i < argc; i++) { if (strcmp(argv[i], "-sb") == 0) { doubleBuffer = GL_FALSE; } else if (strcmp(argv[i], "-db") == 0) { doubleBuffer = GL_TRUE; } else { fprintf(stderr, "%s (Bad option).\n", argv[i]); return GL_FALSE; } } return GL_TRUE; } static void special(int k, int x, int y) { switch (k) { case GLUT_KEY_UP: ty += 1.0; break; case GLUT_KEY_DOWN: ty -= 1.0; break; case GLUT_KEY_LEFT: tx -= 1.0; break; case GLUT_KEY_RIGHT: tx += 1.0; break; default: break; } glutPostRedisplay(); } int main(int argc, char **argv) { GLenum type; glutInit(&argc, argv); if (Args(argc, argv) == GL_FALSE) { exit(1); } glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250); type = GLUT_RGB | GLUT_ALPHA; type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE; glutInitDisplayMode(type); win = glutCreateWindow(*argv); if (!win) { exit(1); } Init(); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutSpecialFunc(special); glutDisplayFunc(Draw); glutMainLoop(); return 0; }