Added new directory of GL shading language demos: glsl

7 files changed, 845 insertions, 0 deletions

diff --git a/progs/glsl/CH06-brick.frag.txt b/progs/glsl/CH06-brick.frag.txt
new file mode 100644
index 0000000000..06ef04e3af
--- /dev/null
+++ b/progs/glsl/CH06-brick.frag.txt
@@ -0,0 +1,36 @@
+//
+// Fragment shader for procedural bricks
+//
+// Authors: Dave Baldwin, Steve Koren, Randi Rost
+//          based on a shader by Darwyn Peachey
+//
+// Copyright (c) 2002-2006 3Dlabs Inc. Ltd. 
+//
+// See 3Dlabs-License.txt for license information
+//
+
+uniform vec3  BrickColor, MortarColor;
+uniform vec2  BrickSize;
+uniform vec2  BrickPct;
+
+varying vec2  MCposition;
+varying float LightIntensity;
+
+void main()
+{
+    vec3  color;
+    vec2  position, useBrick;
+    
+    position = MCposition / BrickSize;
+
+    if (fract(position.y * 0.5) > 0.5)
+        position.x += 0.5;
+
+    position = fract(position);
+
+    useBrick = step(position, BrickPct);
+
+    color  = mix(MortarColor, BrickColor, useBrick.x * useBrick.y);
+    color *= LightIntensity;
+    gl_FragColor = vec4(color, 1.0);
+}
diff --git a/progs/glsl/CH06-brick.vert.txt b/progs/glsl/CH06-brick.vert.txt
new file mode 100644
index 0000000000..e95e6f42f0
--- /dev/null
+++ b/progs/glsl/CH06-brick.vert.txt
@@ -0,0 +1,41 @@
+//
+// Vertex shader for procedural bricks
+//
+// Authors: Dave Baldwin, Steve Koren, Randi Rost
+//          based on a shader by Darwyn Peachey
+//
+// Copyright (c) 2002-2006 3Dlabs Inc. Ltd. 
+//
+// See 3Dlabs-License.txt for license information
+//
+
+uniform vec3 LightPosition;
+
+const float SpecularContribution = 0.3;
+const float DiffuseContribution  = 1.0 - SpecularContribution;
+
+varying float LightIntensity;
+varying vec2  MCposition;
+
+void main()
+{
+    vec3 ecPosition = vec3(gl_ModelViewMatrix * gl_Vertex);
+    vec3 tnorm      = normalize(gl_NormalMatrix * gl_Normal);
+    vec3 lightVec   = normalize(LightPosition - ecPosition);
+    vec3 reflectVec = reflect(-lightVec, tnorm);
+    vec3 viewVec    = normalize(-ecPosition);
+    float diffuse   = max(dot(lightVec, tnorm), 0.0);
+    float spec      = 0.0;
+
+    if (diffuse > 0.0)
+    {
+        spec = max(dot(reflectVec, viewVec), 0.0);
+        spec = pow(spec, 16.0);
+    }
+
+    LightIntensity  = DiffuseContribution * diffuse +
+                      SpecularContribution * spec;
+
+    MCposition      = gl_Vertex.xy;
+    gl_Position     = ftransform();
+}
diff --git a/progs/glsl/CH18-mandel.frag.txt b/progs/glsl/CH18-mandel.frag.txt
new file mode 100644
index 0000000000..3769cffdc8
--- /dev/null
+++ b/progs/glsl/CH18-mandel.frag.txt
@@ -0,0 +1,55 @@
+//
+// Fragment shader for drawing the Mandelbrot set
+//
+// Authors: Dave Baldwin, Steve Koren, Randi Rost
+//          based on a shader by Michael Rivero
+//
+// Copyright (c) 2002-2005: 3Dlabs, Inc.
+//
+// See 3Dlabs-License.txt for license information
+//
+
+varying vec3  Position;
+varying float LightIntensity;
+
+uniform float MaxIterations;
+uniform float Zoom;
+uniform float Xcenter;
+uniform float Ycenter;
+uniform vec3  InnerColor;
+uniform vec3  OuterColor1;
+uniform vec3  OuterColor2;
+
+void main()
+{
+    float   real  = Position.x * Zoom + Xcenter;
+    float   imag  = Position.y * Zoom + Ycenter;
+    float   Creal = real;   // Change this line...
+    float   Cimag = imag;   // ...and this one to get a Julia set
+
+    float r2 = 0.0;
+    float iter;
+
+    for (iter = 0.0; iter < MaxIterations && r2 < 4.0; ++iter)
+//nv:    for (iter = 0.0; iter < 12 && r2 < 4.0; ++iter)
+    {
+        float tempreal = real;
+
+        real = (tempreal * tempreal) - (imag * imag) + Creal;
+        imag = 2.0 * tempreal * imag + Cimag;
+        r2   = (real * real) + (imag * imag);
+    }
+
+    // Base the color on the number of iterations
+
+    vec3 color;
+
+    if (r2 < 4.0)
+        color = InnerColor;
+    else
+        color = mix(OuterColor1, OuterColor2, fract(iter * 0.05));
+
+    color *= LightIntensity;
+
+    gl_FragColor = vec4(color, 1.0);
+}
diff --git a/progs/glsl/CH18-mandel.vert.txt b/progs/glsl/CH18-mandel.vert.txt
new file mode 100644
index 0000000000..c4ca66405d
--- /dev/null
+++ b/progs/glsl/CH18-mandel.vert.txt
@@ -0,0 +1,35 @@
+//
+// Vertex shader for drawing the Mandelbrot set
+//
+// Authors: Dave Baldwin, Steve Koren, Randi Rost
+//          based on a shader by Michael Rivero
+//
+// Copyright (c) 2002-2005: 3Dlabs, Inc.
+//
+// See 3Dlabs-License.txt for license information
+//
+
+uniform vec3 LightPosition;
+uniform float SpecularContribution;
+uniform float DiffuseContribution;
+uniform float Shininess;
+
+varying float LightIntensity;
+varying vec3  Position;
+
+void main()
+{
+    vec3 ecPosition = vec3(gl_ModelViewMatrix * gl_Vertex);
+    vec3 tnorm      = normalize(gl_NormalMatrix * gl_Normal);
+    vec3 lightVec   = normalize(LightPosition - ecPosition);
+    vec3 reflectVec = reflect(-lightVec, tnorm);
+    vec3 viewVec    = normalize(-ecPosition);
+    float spec      = max(dot(reflectVec, viewVec), 0.0);
+    spec            = pow(spec, Shininess);
+    LightIntensity  = DiffuseContribution * 
+                          max(dot(lightVec, tnorm), 0.0) +
+                          SpecularContribution * spec;
+    Position        = vec3(gl_MultiTexCoord0 - 0.5) * 5.0;
+    gl_Position     = ftransform();
+
+}
\ No newline at end of file
diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile
new file mode 100644
index 0000000000..174f5bebe4
--- /dev/null
+++ b/progs/glsl/Makefile
@@ -0,0 +1,50 @@
+# progs/demos/Makefile
+
+TOP = ../..
+include $(TOP)/configs/current
+
+INCDIR = $(TOP)/include
+
+OSMESA_LIBS = -L$(TOP)/$(LIB_DIR) -lglut -lOSMesa -lGLU -lGL $(APP_LIB_DEPS)
+
+OSMESA16_LIBS = -L$(TOP)/$(LIB_DIR) -lglut -lOSMesa16 -lGLU -lGL $(APP_LIB_DEPS)
+
+OSMESA32_LIBS = -L$(TOP)/$(LIB_DIR) -lglut -lOSMesa32 -lGLU -lGL $(APP_LIB_DEPS)
+
+LIB_DEP = $(TOP)/$(LIB_DIR)/$(GL_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLU_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLUT_LIB_NAME)
+
+PROGS = \
+	brick \
+	mandelbrot
+
+
+##### RULES #####
+
+.SUFFIXES:
+.SUFFIXES: .c
+
+
+# make executable from .c file:
+.c: $(LIB_DEP)
+	$(CC) -I$(INCDIR) $(CFLAGS) $< $(APP_LIB_DEPS) -o $@
+
+
+##### TARGETS #####
+
+default: $(PROGS)
+
+$(PROGS):
+
+extfuncs.h:  $(TOP)/progs/util/extfuncs.h
+	cp $< .
+
+
+brick.c: extfuncs.h
+
+mandelbrot.c: extfuncs.h
+
+
+clean:
+	-rm -f $(PROGS)
+	-rm -f *.o *~
+	-rm -f extfuncs.h
diff --git a/progs/glsl/brick.c b/progs/glsl/brick.c
new file mode 100644
index 0000000000..522698b5d4
--- /dev/null
+++ b/progs/glsl/brick.c
@@ -0,0 +1,311 @@
+/**
+ * "Brick" shader demo.  Uses the example shaders from chapter 6 of
+ * the OpenGL Shading Language "orange" book.
+ * 10 Jan 2007
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/gl.h>
+#include <GL/glut.h>
+#include <GL/glext.h>
+#include "extfuncs.h"
+
+
+static char *FragProgFile = "CH06-brick.frag.txt";
+static char *VertProgFile = "CH06-brick.vert.txt";
+
+/* program/shader objects */
+static GLuint fragShader;
+static GLuint vertShader;
+static GLuint program;
+
+
+struct uniform_info {
+   const char *name;
+   GLuint size;
+   GLint location;
+   GLfloat value[4];
+};
+
+static struct uniform_info Uniforms[] = {
+   /* vert */
+   { "LightPosition",     3, -1, { 0.1, 0.1, 9.0, 0} },
+   /* frag */
+   { "BrickColor",        3, -1, { 0.8, 0.2, 0.2, 0 } },
+   { "MortarColor",       3, -1, { 0.6, 0.6, 0.6, 0 } },
+   { "BrickSize",         2, -1, { 1.0, 0.3, 0, 0 } },
+   { "BrickPct",          2, -1, { 0.9, 0.8, 0, 0 } },
+   { NULL, 0, 0, { 0, 0, 0, 0 } }
+};
+
+static GLint win = 0;
+
+
+static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
+
+
+
+
+static void
+Redisplay(void)
+{
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+   
+   glPushMatrix();
+   glRotatef(xRot, 1.0f, 0.0f, 0.0f);
+   glRotatef(yRot, 0.0f, 1.0f, 0.0f);
+   glRotatef(zRot, 0.0f, 0.0f, 1.0f);
+
+   glBegin(GL_POLYGON);
+   glTexCoord2f(0, 0);   glVertex2f(-2, -2);
+   glTexCoord2f(1, 0);   glVertex2f( 2, -2);
+   glTexCoord2f(1, 1);   glVertex2f( 2,  2);
+   glTexCoord2f(0, 1);   glVertex2f(-2,  2);
+   glEnd();
+
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+   glViewport(0, 0, width, height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef(0.0f, 0.0f, -15.0f);
+}
+
+
+static void
+CleanUp(void)
+{
+   glDeleteShader_func(fragShader);
+   glDeleteShader_func(vertShader);
+   glDeleteProgram_func(program);
+   glutDestroyWindow(win);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+  (void) x;
+  (void) y;
+
+   switch(key) {
+   case 'z':
+      zRot -= 1.0;
+      break;
+   case 'Z':
+      zRot += 1.0;
+      break;
+   case 27:
+      CleanUp();
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+   const GLfloat step = 3.0f;
+
+  (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();
+}
+
+
+
+static void
+LoadAndCompileShader(GLuint shader, const char *text)
+{
+   GLint stat;
+
+   glShaderSource_func(shader, 1, (const GLchar **) &text, NULL);
+
+   glCompileShader_func(shader);
+
+   glGetShaderiv_func(shader, GL_COMPILE_STATUS, &stat);
+   if (!stat) {
+      GLchar log[1000];
+      GLsizei len;
+      glGetShaderInfoLog_func(shader, 1000, &len, log);
+      fprintf(stderr, "brick: problem compiling shader: %s\n", log);
+      exit(1);
+   }
+   else {
+      printf("Shader compiled OK\n");
+   }
+}
+
+
+/**
+ * Read a shader from a file.
+ */
+static void
+ReadShader(GLuint shader, const char *filename)
+{
+   const int max = 100*1000;
+   int n;
+   char *buffer = (char*) malloc(max);
+   FILE *f = fopen(filename, "r");
+   if (!f) {
+      fprintf(stderr, "brick: Unable to open shader file %s\n", filename);
+      exit(1);
+   }
+
+   n = fread(buffer, 1, max, f);
+   printf("brick: read %d bytes from shader file %s\n", n, filename);
+   if (n > 0) {
+      buffer[n] = 0;
+      LoadAndCompileShader(shader, buffer);
+   }
+
+   fclose(f);
+   free(buffer);
+}
+
+
+static void
+CheckLink(GLuint prog)
+{
+   GLint stat;
+   glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
+   if (!stat) {
+      GLchar log[1000];
+      GLsizei len;
+      glGetProgramInfoLog_func(prog, 1000, &len, log);
+      fprintf(stderr, "Linker error:\n%s\n", log);
+   }
+   else {
+      fprintf(stderr, "Link success!\n");
+   }
+}
+
+
+static void
+Init(void)
+{
+   const char *version;
+   GLint i;
+
+   version = (const char *) glGetString(GL_VERSION);
+   if (version[0] != '2' || version[1] != '.') {
+      printf("Warning: this program expects OpenGL 2.0\n");
+      /*exit(1);*/
+   }
+
+   GetExtensionFuncs();
+
+   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
+   ReadShader(vertShader, VertProgFile);
+
+   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
+   ReadShader(fragShader, FragProgFile);
+
+   program = glCreateProgram_func();
+   glAttachShader_func(program, fragShader);
+   glAttachShader_func(program, vertShader);
+   glLinkProgram_func(program);
+   CheckLink(program);
+   glUseProgram_func(program);
+
+   for (i = 0; Uniforms[i].name; i++) {
+      Uniforms[i].location
+         = glGetUniformLocation_func(program, Uniforms[i].name);
+      printf("Uniform %s location: %d\n", Uniforms[i].name,
+             Uniforms[i].location);
+      switch (Uniforms[i].size) {
+      case 1:
+         glUniform1fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      case 2:
+         glUniform2fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      case 3:
+         glUniform3fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      case 4:
+         glUniform4fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      default:
+         abort();
+      }
+   }
+
+   assert(glGetError() == 0);
+
+   glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
+
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   assert(glIsProgram_func(program));
+   assert(glIsShader_func(fragShader));
+   assert(glIsShader_func(vertShader));
+
+   glColor3f(1, 0, 0);
+}
+
+
+static void
+ParseOptions(int argc, char *argv[])
+{
+   int i;
+   for (i = 1; i < argc; i++) {
+      if (strcmp(argv[i], "-fs") == 0) {
+         FragProgFile = argv[i+1];
+      }
+      else if (strcmp(argv[i], "-vs") == 0) {
+         VertProgFile = argv[i+1];
+      }
+   }
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowPosition( 0, 0);
+   glutInitWindowSize(400, 400);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+   win = glutCreateWindow(argv[0]);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(Key);
+   glutSpecialFunc(SpecialKey);
+   glutDisplayFunc(Redisplay);
+   ParseOptions(argc, argv);
+   Init();
+   glutMainLoop();
+   return 0;
+}
+
diff --git a/progs/glsl/mandelbrot.c b/progs/glsl/mandelbrot.c
new file mode 100644
index 0000000000..a6c326bfa0
--- /dev/null
+++ b/progs/glsl/mandelbrot.c
@@ -0,0 +1,317 @@
+/**
+ * "Mandelbrot" shader demo.  Uses the example shaders from
+ * chapter 15 (or 18) of the OpenGL Shading Language "orange" book.
+ * 15 Jan 2007
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/gl.h>
+#include <GL/glut.h>
+#include <GL/glext.h>
+#include "extfuncs.h"
+
+
+static char *FragProgFile = "CH18-mandel.frag.txt";
+static char *VertProgFile = "CH18-mandel.vert.txt";
+
+/* program/shader objects */
+static GLuint fragShader;
+static GLuint vertShader;
+static GLuint program;
+
+
+struct uniform_info {
+   const char *name;
+   GLuint size;
+   GLint location;
+   GLfloat value[4];
+};
+
+static struct uniform_info Uniforms[] = {
+   /* vert */
+   { "LightPosition",        3, -1, { 0.1, 0.1, 9.0, 0} },
+   { "SpecularContribution", 1, -1, { 0.5, 0, 0, 0 } },
+   { "DiffuseContribution",  1, -1, { 0.5, 0, 0, 0 } },
+   { "Shininess",            1, -1, { 20.0, 0, 0, 0 } },
+   /* frag */
+   { "MaxIterations",        1, -1, { 12, 0, 0, 0 } },
+   { "Zoom",                 1, -1, { 0.5, 0, 0, 0 } },
+   { "Xcenter",              1, -1, { -1.0, 0, 0, 0 } },
+   { "Ycenter",              1, -1, { .005, 0, 0, 0 } },
+   { "InnerColor",           3, -1, { 1, 0, 0, 0 } },
+   { "OuterColor1",          3, -1, { 0, 1, 0, 0 } },
+   { "OuterColor2",          3, -1, { 0, 0, 1, 0 } },
+   { NULL, 0, 0, { 0, 0, 0, 0 } }
+};
+
+static GLint win = 0;
+
+
+static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
+
+
+
+
+static void
+Redisplay(void)
+{
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+   
+   glPushMatrix();
+   glRotatef(xRot, 1.0f, 0.0f, 0.0f);
+   glRotatef(yRot, 0.0f, 1.0f, 0.0f);
+   glRotatef(zRot, 0.0f, 0.0f, 1.0f);
+
+   glBegin(GL_POLYGON);
+   glTexCoord2f(0, 0);   glVertex2f(-1, -1);
+   glTexCoord2f(1, 0);   glVertex2f( 1, -1);
+   glTexCoord2f(1, 1);   glVertex2f( 1,  1);
+   glTexCoord2f(0, 1);   glVertex2f(-1,  1);
+   glEnd();
+
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+   glViewport(0, 0, width, height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef(0.0f, 0.0f, -6.0f);
+}
+
+
+static void
+CleanUp(void)
+{
+   glDeleteShader_func(fragShader);
+   glDeleteShader_func(vertShader);
+   glDeleteProgram_func(program);
+   glutDestroyWindow(win);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+  (void) x;
+  (void) y;
+
+   switch(key) {
+   case 'z':
+      zRot -= 1.0;
+      break;
+   case 'Z':
+      zRot += 1.0;
+      break;
+   case 27:
+      CleanUp();
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+   const GLfloat step = 3.0f;
+
+  (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();
+}
+
+
+
+static void
+LoadAndCompileShader(GLuint shader, const char *text)
+{
+   GLint stat;
+
+   glShaderSource_func(shader, 1, (const GLchar **) &text, NULL);
+
+   glCompileShader_func(shader);
+
+   glGetShaderiv_func(shader, GL_COMPILE_STATUS, &stat);
+   if (!stat) {
+      GLchar log[1000];
+      GLsizei len;
+      glGetShaderInfoLog_func(shader, 1000, &len, log);
+      fprintf(stderr, "brick: problem compiling shader: %s\n", log);
+      exit(1);
+   }
+   else {
+      printf("Shader compiled OK\n");
+   }
+}
+
+
+/**
+ * Read a shader from a file.
+ */
+static void
+ReadShader(GLuint shader, const char *filename)
+{
+   const int max = 100*1000;
+   int n;
+   char *buffer = (char*) malloc(max);
+   FILE *f = fopen(filename, "r");
+   if (!f) {
+      fprintf(stderr, "brick: Unable to open shader file %s\n", filename);
+      exit(1);
+   }
+
+   n = fread(buffer, 1, max, f);
+   printf("brick: read %d bytes from shader file %s\n", n, filename);
+   if (n > 0) {
+      buffer[n] = 0;
+      LoadAndCompileShader(shader, buffer);
+   }
+
+   fclose(f);
+   free(buffer);
+}
+
+
+static void
+CheckLink(GLuint prog)
+{
+   GLint stat;
+   glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
+   if (!stat) {
+      GLchar log[1000];
+      GLsizei len;
+      glGetProgramInfoLog_func(prog, 1000, &len, log);
+      fprintf(stderr, "Linker error:\n%s\n", log);
+   }
+   else {
+      fprintf(stderr, "Link success!\n");
+   }
+}
+
+
+static void
+Init(void)
+{
+   const char *version;
+   GLint i;
+
+   version = (const char *) glGetString(GL_VERSION);
+   if (version[0] != '2' || version[1] != '.') {
+      printf("Warning: this program expects OpenGL 2.0\n");
+      /*exit(1);*/
+   }
+
+   GetExtensionFuncs();
+
+   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
+   ReadShader(vertShader, VertProgFile);
+
+   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
+   ReadShader(fragShader, FragProgFile);
+
+   program = glCreateProgram_func();
+   glAttachShader_func(program, fragShader);
+   glAttachShader_func(program, vertShader);
+   glLinkProgram_func(program);
+   CheckLink(program);
+   glUseProgram_func(program);
+
+   for (i = 0; Uniforms[i].name; i++) {
+      Uniforms[i].location
+         = glGetUniformLocation_func(program, Uniforms[i].name);
+      printf("Uniform %s location: %d\n", Uniforms[i].name,
+             Uniforms[i].location);
+      switch (Uniforms[i].size) {
+      case 1:
+         glUniform1fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      case 2:
+         glUniform2fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      case 3:
+         glUniform3fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      case 4:
+         glUniform4fv_func(Uniforms[i].location, 1, Uniforms[i].value);
+         break;
+      default:
+         abort();
+      }
+   }
+
+   assert(glGetError() == 0);
+
+   glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
+
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   assert(glIsProgram_func(program));
+   assert(glIsShader_func(fragShader));
+   assert(glIsShader_func(vertShader));
+
+   glColor3f(1, 0, 0);
+}
+
+
+static void
+ParseOptions(int argc, char *argv[])
+{
+   int i;
+   for (i = 1; i < argc; i++) {
+      if (strcmp(argv[i], "-fs") == 0) {
+         FragProgFile = argv[i+1];
+      }
+      else if (strcmp(argv[i], "-vs") == 0) {
+         VertProgFile = argv[i+1];
+      }
+   }
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowPosition( 0, 0);
+   glutInitWindowSize(400, 400);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+   win = glutCreateWindow(argv[0]);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(Key);
+   glutSpecialFunc(SpecialKey);
+   glutDisplayFunc(Redisplay);
+   ParseOptions(argc, argv);
+   Init();
+   glutMainLoop();
+   return 0;
+}
+