Added toyball and bumpmap tests using shaders from the OpenGL Shading Language (orange) book.

8 files changed, 854 insertions, 4 deletions

diff --git a/progs/glsl/CH11-bumpmap.frag.txt b/progs/glsl/CH11-bumpmap.frag.txt
new file mode 100644
index 0000000000..063576f5a3
--- /dev/null
+++ b/progs/glsl/CH11-bumpmap.frag.txt
@@ -0,0 +1,41 @@
+//
+// Fragment shader for procedural bumps
+//
+// Authors: John Kessenich, Randi Rost
+//
+// Copyright (c) 2002-2006 3Dlabs Inc. Ltd. 
+//
+// See 3Dlabs-License.txt for license information
+//
+
+varying vec3 LightDir;
+varying vec3 EyeDir;
+
+uniform vec3  SurfaceColor;    // = (0.7, 0.6, 0.18)
+uniform float BumpDensity;     // = 16.0
+uniform float BumpSize;        // = 0.15
+uniform float SpecularFactor;  // = 0.5
+
+void main()
+{
+    vec3 litColor;
+    vec2 c = BumpDensity * gl_TexCoord[0].st;
+    vec2 p = fract(c) - vec2(0.5);
+
+    float d, f;
+    d = p.x * p.x + p.y * p.y;
+    f = 1.0 / sqrt(d + 1.0);
+
+    if (d >= BumpSize)
+        { p = vec2(0.0); f = 1.0; }
+
+    vec3 normDelta = vec3(p.x, p.y, 1.0) * f;
+    litColor = SurfaceColor * max(dot(normDelta, LightDir), 0.0);
+    vec3 reflectDir = reflect(LightDir, normDelta);
+    
+    float spec = max(dot(EyeDir, reflectDir), 0.0);
+    spec *= SpecularFactor;
+    litColor = min(litColor + spec, vec3(1.0));
+
+    gl_FragColor = vec4(litColor, 1.0);
+}
diff --git a/progs/glsl/CH11-bumpmap.vert.txt b/progs/glsl/CH11-bumpmap.vert.txt
new file mode 100644
index 0000000000..d3d19f62ac
--- /dev/null
+++ b/progs/glsl/CH11-bumpmap.vert.txt
@@ -0,0 +1,38 @@
+//
+// Vertex shader for procedural bumps
+//
+// Authors: Randi Rost, John Kessenich
+//
+// Copyright (c) 2002-2006 3Dlabs Inc. Ltd. 
+//
+// See 3Dlabs-License.txt for license information
+//
+
+varying vec3 LightDir;
+varying vec3 EyeDir;
+
+uniform vec3 LightPosition;
+
+attribute vec3 Tangent;
+
+void main() 
+{
+    EyeDir         = vec3(gl_ModelViewMatrix * gl_Vertex);
+    gl_Position    = ftransform();
+    gl_TexCoord[0] = gl_MultiTexCoord0;
+
+    vec3 n = normalize(gl_NormalMatrix * gl_Normal);
+    vec3 t = normalize(gl_NormalMatrix * Tangent);
+    vec3 b = cross(n, t);
+
+    vec3 v;
+    v.x = dot(LightPosition, t);
+    v.y = dot(LightPosition, b);
+    v.z = dot(LightPosition, n);
+    LightDir = normalize(v);
+
+    v.x = dot(EyeDir, t);
+    v.y = dot(EyeDir, b);
+    v.z = dot(EyeDir, n);
+    EyeDir = normalize(v);
+}
diff --git a/progs/glsl/CH11-toyball.frag.txt b/progs/glsl/CH11-toyball.frag.txt
new file mode 100644
index 0000000000..cf9129ee1d
--- /dev/null
+++ b/progs/glsl/CH11-toyball.frag.txt
@@ -0,0 +1,79 @@
+//
+// Fragment shader for procedurally generated toy ball
+//
+// Author: Bill Licea-Kane
+//
+// Copyright (c) 2002-2003 ATI Research 
+//
+// See ATI-License.txt for license information
+//
+
+varying vec4 ECposition;   // surface position in eye coordinates
+varying vec4 ECballCenter; // ball center in eye coordinates
+
+uniform vec4  LightDir;     // light direction, should be normalized
+uniform vec4  HVector;      // reflection vector for infinite light source
+uniform vec4  SpecularColor;
+uniform vec4  Red, Yellow, Blue;
+
+uniform vec4  HalfSpace0;   // half-spaces used to define star pattern
+uniform vec4  HalfSpace1;
+uniform vec4  HalfSpace2;
+uniform vec4  HalfSpace3;
+uniform vec4  HalfSpace4;
+
+uniform float InOrOutInit;  // = -3
+uniform float StripeWidth;  // = 0.3
+uniform float FWidth;       // = 0.005
+
+void main()
+{
+    vec4  normal;              // Analytically computed normal
+    vec4  p;                   // Point in shader space
+    vec4  surfColor;           // Computed color of the surface
+    float intensity;           // Computed light intensity
+    vec4  distance;            // Computed distance values
+    float inorout;             // Counter for computing star pattern
+
+    p.xyz = normalize(ECposition.xyz - ECballCenter.xyz);    // Calculate p
+    p.w   = 1.0;
+
+    inorout = InOrOutInit;     // initialize inorout to -3
+
+    distance[0] = dot(p, HalfSpace0);
+    distance[1] = dot(p, HalfSpace1);
+    distance[2] = dot(p, HalfSpace2);
+    distance[3] = dot(p, HalfSpace3);
+
+#if 1
+    distance = smoothstep(-FWidth, FWidth, distance);
+    inorout += dot(distance, vec4(1.0));
+
+    distance.x = dot(p, HalfSpace4);
+    distance.y = StripeWidth - abs(p.z);
+    distance = smoothstep(-FWidth, FWidth, distance);
+    inorout += distance.x;
+
+    inorout = clamp(inorout, 0.0, 1.0);
+
+    surfColor = mix(Yellow, Red, inorout);
+    surfColor = mix(surfColor, Blue, distance.y);
+
+    // normal = point on surface for sphere at (0,0,0)
+    normal = p;
+
+    // Per fragment diffuse lighting
+    intensity  = 0.2; // ambient
+    intensity += 0.8 * clamp(dot(LightDir, normal), 0.0, 1.0);
+    surfColor *= intensity;
+
+    // Per fragment specular lighting
+    intensity  = clamp(dot(HVector, normal), 0.0, 1.0);
+    intensity  = pow(intensity, SpecularColor.a);
+    surfColor += SpecularColor * intensity;
+
+    gl_FragColor = surfColor;
+#else
+    gl_FragColor = distance;
+#endif
+}
diff --git a/progs/glsl/CH11-toyball.vert.txt b/progs/glsl/CH11-toyball.vert.txt
new file mode 100644
index 0000000000..21795c17cd
--- /dev/null
+++ b/progs/glsl/CH11-toyball.vert.txt
@@ -0,0 +1,20 @@
+//
+// Fragment shader for procedurally generated toy ball
+//
+// Author: Bill Licea-Kane
+//
+// Copyright (c) 2002-2003 ATI Research 
+//
+// See ATI-License.txt for license information
+//
+
+varying vec4 ECposition;   // surface position in eye coordinates
+varying vec4 ECballCenter; // ball center in eye coordinates
+uniform vec4 BallCenter;   // ball center in modelling coordinates
+
+void main()
+{ 
+    ECposition   = gl_ModelViewMatrix * gl_Vertex;
+    ECballCenter = gl_ModelViewMatrix * BallCenter;
+    gl_Position  = ftransform();
+}
\ No newline at end of file
diff --git a/progs/glsl/CH18-mandel.frag.txt b/progs/glsl/CH18-mandel.frag.txt
index 3769cffdc8..a472d81252 100644
--- a/progs/glsl/CH18-mandel.frag.txt
+++ b/progs/glsl/CH18-mandel.frag.txt
@@ -30,8 +30,8 @@ void main()
     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)
+//    for (iter = 0.0; iter < MaxIterations && r2 < 4.0; ++iter)
+    for (iter = 0.0; iter < 12 && r2 < 4.0; ++iter)
     {
         float tempreal = real;
 
diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile
index 174f5bebe4..fa7f191986 100644
--- a/progs/glsl/Makefile
+++ b/progs/glsl/Makefile
@@ -15,7 +15,9 @@ LIB_DEP = $(TOP)/$(LIB_DIR)/$(GL_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLU_LIB_NAME) $(T
 
 PROGS = \
 	brick \
-	mandelbrot
+	bump \
+	mandelbrot \
+	toyball
 
 
 ##### RULES #####
@@ -33,7 +35,9 @@ PROGS = \
 
 default: $(PROGS)
 
-$(PROGS):
+
+
+##### Extra dependencies
 
 extfuncs.h:  $(TOP)/progs/util/extfuncs.h
 	cp $< .
@@ -41,8 +45,12 @@ extfuncs.h:  $(TOP)/progs/util/extfuncs.h
 
 brick.c: extfuncs.h
 
+bump.c: extfuncs.h
+
 mandelbrot.c: extfuncs.h
 
+toyball.c: extfuncs.h
+
 
 clean:
 	-rm -f $(PROGS)
diff --git a/progs/glsl/bump.c b/progs/glsl/bump.c
new file mode 100644
index 0000000000..b71c3af970
--- /dev/null
+++ b/progs/glsl/bump.c
@@ -0,0 +1,348 @@
+/**
+ * Procedural Bump Mapping demo.  Uses the example shaders from
+ * chapter 11 of the OpenGL Shading Language "orange" book.
+ * 16 Jan 2007
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+#include <GL/glu.h>
+#include <GL/glext.h>
+#include "extfuncs.h"
+
+
+static char *FragProgFile = "CH11-bumpmap.frag.txt";
+static char *VertProgFile = "CH11-bumpmap.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[] = {
+   { "LightPosition",       3, -1, { 0.57737, 0.57735, 0.57735, 0.0 } },
+   { "SurfaceColor",        3, -1, { 0.8, 0.8, 0.2, 0 } },
+   { "BumpDensity",         1, -1, { 16.0, 0, 0, 0 } },
+   { "BumpSize",            1, -1, { 0.15, 0, 0, 0 } },
+   { "SpecularFactor",      1, -1, { 0.5, 0, 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 GLuint tangentAttrib;
+
+
+static void
+CheckError(int line)
+{
+   GLenum err = glGetError();
+   if (err) {
+      printf("GL Error %s (0x%x) at line %d\n",
+             gluErrorString(err), (int) err, line);
+   }
+}
+
+/*
+ * Draw a square, specifying normal and tangent vectors.
+ */
+static void
+Square(GLfloat size)
+{
+   glNormal3f(0, 0, 1);
+   glVertexAttrib3f_func(tangentAttrib, 1, 0, 0);
+   glBegin(GL_POLYGON);
+   glTexCoord2f(0, 0);  glVertex2f(-size, -size);
+   glTexCoord2f(1, 0);  glVertex2f( size, -size);
+   glTexCoord2f(1, 1);  glVertex2f( size,  size);
+   glTexCoord2f(0, 1);  glVertex2f(-size,  size);
+   glEnd();
+}
+
+
+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);
+
+   Square(2.0);
+
+   glPopMatrix();
+
+   glFinish();
+   glFlush();
+
+   CheckError(__LINE__);
+
+   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)
+{
+   const GLfloat step = 2.0;
+  (void) x;
+  (void) y;
+
+   switch(key) {
+   case 'z':
+      zRot += step;
+      break;
+   case 'Z':
+      zRot -= step;
+      break;
+   case 27:
+      CleanUp();
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+   const 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();
+}
+
+
+
+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);*/
+   }
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   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);
+
+   assert(glIsProgram_func(program));
+   assert(glIsShader_func(fragShader));
+   assert(glIsShader_func(vertShader));
+
+   assert(glGetError() == 0);
+
+   CheckError(__LINE__);
+
+   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();
+      }
+   }
+
+   CheckError(__LINE__);
+
+   tangentAttrib = glGetAttribLocation_func(program, "Tangent");
+   printf("Tangent Attrib: %d\n", tangentAttrib);
+
+   assert(tangentAttrib >= 0);
+
+   CheckError(__LINE__);
+
+   glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
+
+   glEnable(GL_DEPTH_TEST);
+
+   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/toyball.c b/progs/glsl/toyball.c
new file mode 100644
index 0000000000..2d3462fc61
--- /dev/null
+++ b/progs/glsl/toyball.c
@@ -0,0 +1,316 @@
+/**
+ * "Toy Ball" shader demo.  Uses the example shaders from
+ * chapter 11 of the OpenGL Shading Language "orange" book.
+ * 16 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 = "CH11-toyball.frag.txt";
+static char *VertProgFile = "CH11-toyball.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[] = {
+   { "LightDir",       4, -1, { 0.57737, 0.57735, 0.57735, 0.0 } },
+   { "HVector",        4, -1, { 0.32506, 0.32506, 0.88808, 0.0 } },
+   { "BallCenter",     4, -1, { 0.0, 0.0, 0.0, 1.0 } },
+   { "SpecularColor",  4, -1, { 0.4, 0.4, 0.4, 60.0 } },
+   { "Red",            4, -1, { 0.6, 0.0, 0.0, 1.0 } },
+   { "Blue",           4, -1, { 0.0, 0.3, 0.6, 1.0 } },
+   { "Yellow",         4, -1, { 0.6, 0.5, 0.0, 1.0 } },
+   { "HalfSpace0",     4, -1, { 1.0, 0.0, 0.0, 0.2 } },
+   { "HalfSpace1",     4, -1, { 0.309016994, 0.951056516, 0.0, 0.2 } },
+   { "HalfSpace2",     4, -1, { -0.809016994, 0.587785252, 0.0, 0.2 } },
+   { "HalfSpace3",     4, -1, { -0.809016994, -0.587785252, 0.0, 0.2 } },
+   { "HalfSpace4",     4, -1, { 0.309116994, -0.951056516, 0.0, 0.2 } },
+   { "InOrOutInit",    1, -1, { -3.0, 0, 0, 0 } },
+   { "StripeWidth",    1, -1, {  0.3, 0, 0, 0 } },
+   { "FWidth",         1, -1, { 0.005, 0, 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);
+
+   glutSolidSphere(2.0, 20, 10);
+
+   glPopMatrix();
+
+   glFinish();
+   glFlush();
+   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)
+{
+   const GLfloat step = 2.0;
+  (void) x;
+  (void) y;
+
+   switch(key) {
+   case 'z':
+      zRot += step;
+      break;
+   case 'Z':
+      zRot -= step;
+      break;
+   case 27:
+      CleanUp();
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+   const 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();
+}
+
+
+
+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);*/
+   }
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   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);
+
+   assert(glIsProgram_func(program));
+   assert(glIsShader_func(fragShader));
+   assert(glIsShader_func(vertShader));
+
+
+   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);
+
+   glEnable(GL_DEPTH_TEST);
+
+   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;
+}
+