new multi-texture GLSL test

progs/glsl/Makefile

@@ -15,6 +15,7 @@ PROGS = \
 	bump \
 	deriv \
 	mandelbrot \
+	multitex \
 	noise \
 	points \
 	texdemo1 \
@@ -102,6 +103,13 @@ mandelbrot: mandelbrot.o shaderutil.o
 	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) mandelbrot.o shaderutil.o $(LIBS) -o $@
 
 
+multitex.o: multitex.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) multitex.c
+
+multitex: multitex.o readtex.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) multitex.o readtex.o shaderutil.o $(LIBS) -o $@
+
+
 noise.o: noise.c extfuncs.h shaderutil.h
 	$(CC) -c -I$(INCDIR) $(CFLAGS) noise.c
 

progs/glsl/multitex.c

@@ -0,0 +1,285 @@
+/**
+ * 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;
+}

progs/glsl/multitex.frag.txt

@@ -0,0 +1,15 @@
+// Multi-texture fragment shader
+// Brian Paul
+
+// Composite second texture over first.
+// We're assuming the 2nd texture has a meaningful alpha channel.
+
+uniform sampler2D tex1;
+uniform sampler2D tex2;
+
+void main()
+{
+   vec4 t1 = texture2D(tex1, gl_TexCoord[0].xy, 0.0);
+   vec4 t2 = texture2D(tex2, gl_TexCoord[1].xy, 0.0);
+   gl_FragColor = mix(t1, t2, t2.w);
+}

progs/glsl/multitex.vert.txt

@@ -0,0 +1,10 @@
+// Multi-texture vertex shader
+// Brian Paul
+
+
+void main() 
+{
+   gl_TexCoord[0] = gl_MultiTexCoord0;
+   gl_TexCoord[1] = gl_MultiTexCoord1;
+   gl_Position = ftransform();
+}