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-rw-r--r--progs/trivial/quad-tex-alpha.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/progs/trivial/quad-tex-alpha.c b/progs/trivial/quad-tex-alpha.c
new file mode 100644
index 0000000000..cd73f013eb
--- /dev/null
+++ b/progs/trivial/quad-tex-alpha.c
@@ -0,0 +1,170 @@
+/*
+ * 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();
+
+
+ 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;
+}