--- /dev/null
+/**
+ * Test multi-texturing with GL shading language.
+ *
+ * Copyright (C) 2008 Brian Paul All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "GL/glut.h"
+#include "readtex.h"
+#include "extfuncs.h"
+#include "shaderutil.h"
+
+static const char *Demo = "multitex";
+
+static const char *VertFile = "multitex.vert.txt";
+static const char *FragFile = "multitex.frag.txt";
+
+static const char *TexFiles[2] =
+ {
+ "../images/tile.rgb",
+ "../images/tree2.rgba"
+ };
+
+
+static GLuint Program;
+
+static GLfloat Xrot = -90.0, Yrot = .0, Zrot = 0.0;
+static GLfloat EyeDist = 10;
+static GLboolean Anim = GL_TRUE;
+
+
+/* value[0] = tex unit */
+static struct uniform_info Uniforms[] = {
+ { "tex1", 1, GL_INT, { 0, 0, 0, 0 }, -1 },
+ { "tex2", 1, GL_INT, { 1, 0, 0, 0 }, -1 },
+ END_OF_UNIFORMS
+};
+
+
+static void
+DrawPolygon(GLfloat size)
+{
+ glPushMatrix();
+ glRotatef(90, 1, 0, 0);
+ glNormal3f(0, 0, 1);
+ glBegin(GL_POLYGON);
+
+ glMultiTexCoord2f(GL_TEXTURE0, 0, 0);
+ glMultiTexCoord2f(GL_TEXTURE1, 0, 0);
+ glVertex2f(-size, -size);
+
+ glMultiTexCoord2f(GL_TEXTURE0, 2, 0);
+ glMultiTexCoord2f(GL_TEXTURE1, 1, 0);
+ glVertex2f( size, -size);
+
+ glMultiTexCoord2f(GL_TEXTURE0, 2, 2);
+ glMultiTexCoord2f(GL_TEXTURE1, 1, 1);
+ glVertex2f( size, size);
+
+ glMultiTexCoord2f(GL_TEXTURE0, 0, 2);
+ glMultiTexCoord2f(GL_TEXTURE1, 0, 1);
+ glVertex2f(-size, size);
+
+ glEnd();
+ glPopMatrix();
+}
+
+
+static void
+draw(void)
+{
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ glPushMatrix(); /* modelview matrix */
+ glTranslatef(0.0, 0.0, -EyeDist);
+ glRotatef(Zrot, 0, 0, 1);
+ glRotatef(Yrot, 0, 1, 0);
+ glRotatef(Xrot, 1, 0, 0);
+
+ DrawPolygon(3.0);
+
+ glPopMatrix();
+
+ glutSwapBuffers();
+}
+
+
+static void
+idle(void)
+{
+ GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
+ Yrot = t;
+ glutPostRedisplay();
+}
+
+
+static void
+key(unsigned char k, int x, int y)
+{
+ (void) x;
+ (void) y;
+ switch (k) {
+ case ' ':
+ case 'a':
+ Anim = !Anim;
+ if (Anim)
+ glutIdleFunc(idle);
+ else
+ glutIdleFunc(NULL);
+ break;
+ case 'z':
+ EyeDist -= 0.5;
+ if (EyeDist < 3.0)
+ EyeDist = 3.0;
+ break;
+ case 'Z':
+ EyeDist += 0.5;
+ if (EyeDist > 90.0)
+ EyeDist = 90;
+ break;
+ case 27:
+ exit(0);
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+specialkey(int key, int x, int y)
+{
+ GLfloat step = 2.0;
+ (void) x;
+ (void) y;
+ switch (key) {
+ case GLUT_KEY_UP:
+ Xrot += step;
+ break;
+ case GLUT_KEY_DOWN:
+ Xrot -= step;
+ break;
+ case GLUT_KEY_LEFT:
+ Yrot -= step;
+ break;
+ case GLUT_KEY_RIGHT:
+ Yrot += step;
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+/* new window size or exposure */
+static void
+Reshape(int width, int height)
+{
+ GLfloat ar = (float) width / (float) height;
+ glViewport(0, 0, (GLint)width, (GLint)height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+}
+
+
+static void
+InitTextures(void)
+{
+ GLenum filter = GL_LINEAR;
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ GLint imgWidth, imgHeight;
+ GLenum imgFormat;
+ GLubyte *image = NULL;
+
+ image = LoadRGBImage(TexFiles[i], &imgWidth, &imgHeight, &imgFormat);
+ if (!image) {
+ printf("Couldn't read %s\n", TexFiles[i]);
+ exit(0);
+ }
+
+ glActiveTexture(GL_TEXTURE0 + i);
+ glBindTexture(GL_TEXTURE_2D, 42 + i);
+ gluBuild2DMipmaps(GL_TEXTURE_2D, 4, imgWidth, imgHeight,
+ imgFormat, GL_UNSIGNED_BYTE, image);
+ free(image);
+
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
+ }
+}
+
+
+static GLuint
+CreateProgram(const char *vertProgFile, const char *fragProgFile,
+ struct uniform_info *uniforms)
+{
+ GLuint fragShader, vertShader, program;
+
+ vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
+ fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
+ assert(vertShader);
+ program = LinkShaders(vertShader, fragShader);
+
+ glUseProgram_func(program);
+
+ InitUniforms(program, uniforms);
+
+ return program;
+}
+
+
+static void
+InitPrograms(void)
+{
+ Program = CreateProgram(VertFile, FragFile, Uniforms);
+}
+
+
+static void
+InitGL(void)
+{
+ const char *version = (const char *) glGetString(GL_VERSION);
+
+ if (version[0] != '2' || version[1] != '.') {
+ printf("Warning: this program expects OpenGL 2.0\n");
+ /*exit(1);*/
+ }
+ printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+ GetExtensionFuncs();
+
+ InitTextures();
+ InitPrograms();
+
+ glEnable(GL_DEPTH_TEST);
+
+ glClearColor(.6, .6, .9, 0);
+ glColor3f(1.0, 1.0, 1.0);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowSize(500, 400);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+ glutCreateWindow(Demo);
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(key);
+ glutSpecialFunc(specialkey);
+ glutDisplayFunc(draw);
+ if (Anim)
+ glutIdleFunc(idle);
+ InitGL();
+ glutMainLoop();
+ return 0;
+}