diff options
Diffstat (limited to 'progs/trivial/tri-alpha-tex.c')
| -rw-r--r-- | progs/trivial/tri-alpha-tex.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/progs/trivial/tri-alpha-tex.c b/progs/trivial/tri-alpha-tex.c new file mode 100644 index 00000000000..776f39dcc35 --- /dev/null +++ b/progs/trivial/tri-alpha-tex.c @@ -0,0 +1,179 @@ +/* + * 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 <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <GL/glut.h> + + +#define CI_OFFSET_1 16 +#define CI_OFFSET_2 32 + + +GLenum doubleBuffer; + +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)); + + glClearColor(0.0, 0.0, 1.0, 0.0); + +#define SIZE 16 + { + GLubyte tex2d[SIZE][SIZE][4]; + GLint s, t; + + for (s = 0; s < SIZE; s++) { + for (t = 0; t < SIZE; t++) { + tex2d[t][s][0] = (s < SIZE/2) ? 0 : 255; + tex2d[t][s][1] = (t < SIZE/2) ? 0 : 255; + tex2d[t][s][2] = 0; + tex2d[t][s][3] = ((t^s) & 3) * 63; + } + } + + glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); + glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_REPEAT); + glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); + + glPixelStorei(GL_UNPACK_ALIGNMENT, 1); + glTexImage2D(GL_TEXTURE_2D, 0, 4, SIZE, SIZE, 0, + GL_RGBA, GL_UNSIGNED_BYTE, tex2d); + glPixelStorei(GL_UNPACK_ALIGNMENT, 4); + glEnable(GL_TEXTURE_2D); + } +} + +static void Reshape(int width, int height) +{ + + glViewport(0, 0, (GLint)width, (GLint)height); + + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); + glMatrixMode(GL_MODELVIEW); +} + +static void Key(unsigned char key, int x, int y) +{ + + switch (key) { + case 27: + exit(1); + default: + return; + } + + glutPostRedisplay(); +} + +static void Draw(void) +{ + glClear(GL_COLOR_BUFFER_BIT); + + glDisable(GL_DEPTH_TEST); + glDisable(GL_STENCIL_TEST); + glEnable(GL_ALPHA_TEST); + glAlphaFunc(GL_GEQUAL, 0.5); + + glBegin(GL_QUADS); + glTexCoord2f(1,0); + glVertex3f( 0.9, -0.9, -30.0); + glTexCoord2f(1,1); + glVertex3f( 0.9, 0.9, -30.0); + glTexCoord2f(0,1); + glVertex3f(-0.9, 0.9, -30.0); + glTexCoord2f(0,0); + glVertex3f(-0.9, -0.9, -30.0); + glEnd(); +#if 0 + glBegin(GL_TRIANGLES); + glColor4f(0,0,.7,1); + glVertex3f( 0.9, -0.9, -30.0); + glColor4f(.8,0,0,.5); + glVertex3f( 0.9, 0.9, -30.0); + glColor4f(0,.9,0,0); + glVertex3f(-0.9, 0.0, -30.0); + glEnd(); +#endif + + glFlush(); + + if (doubleBuffer) { + glutSwapBuffers(); + } +} + +static GLenum Args(int argc, char **argv) +{ + GLint i; + + doubleBuffer = GL_FALSE; + + 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; +} + +int main(int argc, char **argv) +{ + GLenum type; + + glutInit(&argc, argv); + + if (Args(argc, argv) == GL_FALSE) { + exit(1); + } + + glutInitWindowPosition(100, 0); glutInitWindowSize( 250, 250); + + type = GLUT_RGB; + type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE; + glutInitDisplayMode(type); + + if (glutCreateWindow("First Tri") == GL_FALSE) { + exit(1); + } + + Init(); + + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutDisplayFunc(Draw); + glutMainLoop(); + return 0; +} |