Replace duplicated code with new shaderutil.c functions

12 files changed, 200 insertions, 1075 deletions

diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile
index 5ee7a8e3d4..64be144e0f 100644
--- a/progs/glsl/Makefile
+++ b/progs/glsl/Makefile
@@ -45,6 +45,7 @@ default: $(PROGS)
 extfuncs.h:  $(TOP)/progs/util/extfuncs.h
 	cp $< .
 
+
 readtex.c: $(TOP)/progs/util/readtex.c
 	cp $< .
 
@@ -54,24 +55,97 @@ readtex.h: $(TOP)/progs/util/readtex.h
 readtex.o: readtex.c readtex.h
 	$(CC) -c -I$(INCDIR) $(CFLAGS) readtex.c
 
-bitmap.c: extfuncs.h
 
-brick.c: extfuncs.h
+shaderutil.c: $(TOP)/progs/util/shaderutil.c
+	cp $< .
+
+shaderutil.h: $(TOP)/progs/util/shaderutil.h
+	cp $< .
+
+shaderutil.o: shaderutil.c shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) shaderutil.c
+
+
+
+bitmap.o: bitmap.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) bitmap.c
+
+bitmap: bitmap.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) bitmap.o shaderutil.o $(LIBS) -o $@
+
+
+brick.o: brick.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) brick.c
+
+brick: brick.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) brick.o shaderutil.o $(LIBS) -o $@
+
+
+bump.o: bump.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) bump.c
+
+bump: bump.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) bump.o shaderutil.o $(LIBS) -o $@
+
+
+deriv.o: deriv.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) deriv.c
+
+deriv: deriv.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) deriv.o shaderutil.o $(LIBS) -o $@
 
-bump.c: extfuncs.h
 
-mandelbrot.c: extfuncs.h
+mandelbrot.o: mandelbrot.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) mandelbrot.c
 
-points.c: extfuncs.h
+mandelbrot: mandelbrot.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) mandelbrot.o shaderutil.o $(LIBS) -o $@
 
-toyball.c: extfuncs.h
 
-texdemo1: texdemo1.o readtex.o
-	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) texdemo1.o readtex.o $(LIBS) -o $@
+noise.o: noise.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) noise.c
 
-texdemo1.o: texdemo1.c readtex.h extfuncs.h
+noise: noise.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) noise.o shaderutil.o $(LIBS) -o $@
+
+
+points.o: points.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) points.c
+
+points: points.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) points.o shaderutil.o $(LIBS) -o $@
+
+
+texdemo1.o: texdemo1.c readtex.h extfuncs.h shaderutil.h
 	$(CC) -c -I$(INCDIR) $(CFLAGS) texdemo1.c
 
+texdemo1: texdemo1.o readtex.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) texdemo1.o readtex.o shaderutil.o $(LIBS) -o $@
+
+
+toyball.o: toyball.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) toyball.c
+
+toyball: toyball.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) toyball.o shaderutil.o $(LIBS) -o $@
+
+
+twoside.o: twoside.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) twoside.c
+
+twoside: twoside.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) twoside.o shaderutil.o $(LIBS) -o $@
+
+
+trirast.o: trirast.c extfuncs.h shaderutil.h
+	$(CC) -c -I$(INCDIR) $(CFLAGS) trirast.c
+
+trirast: trirast.o shaderutil.o
+	$(CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) trirast.o shaderutil.o $(LIBS) -o $@
+
+
+
+
 
 clean:
 	-rm -f $(PROGS)
diff --git a/progs/glsl/bitmap.c b/progs/glsl/bitmap.c
index 4b62686cbf..d488ec6cb9 100644
--- a/progs/glsl/bitmap.c
+++ b/progs/glsl/bitmap.c
@@ -13,6 +13,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static GLuint FragShader;
@@ -247,40 +248,6 @@ MakeBitmapTextures(void)
 
 
 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, "fslight: problem compiling shader:\n%s\n", log);
-      exit(1);
-   }
-}
-
-
-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);
-   }
-}
-
-
-static void
 Init(void)
 {
    /* Fragment shader: modulate raster color by texture, discard fragments
@@ -306,28 +273,16 @@ Init(void)
       "   gl_TexCoord[0] = gl_MultiTexCoord0; \n"
       "   gl_FrontColor = gl_Color; \n"
       "}\n";
-   const char *version;
 
-   version = (const char *) glGetString(GL_VERSION);
-   if (version[0] != '2' || version[1] != '.') {
-      printf("This program requires OpenGL 2.x, found %s\n", version);
+   if (!ShadersSupported())
       exit(1);
-   }
-   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 
    GetExtensionFuncs();
 
-   FragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   LoadAndCompileShader(FragShader, fragShaderText);
-
-   VertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   LoadAndCompileShader(VertShader, vertShaderText);
+   VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+   FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+   Program = LinkShaders(VertShader, FragShader);
 
-   Program = glCreateProgram_func();
-   glAttachShader_func(Program, FragShader);
-   glAttachShader_func(Program, VertShader);
-   glLinkProgram_func(Program);
-   CheckLink(Program);
    glUseProgram_func(Program);
 
    uScale = glGetUniformLocation_func(Program, "scale");
diff --git a/progs/glsl/brick.c b/progs/glsl/brick.c
index 522698b5d4..4be266622b 100644
--- a/progs/glsl/brick.c
+++ b/progs/glsl/brick.c
@@ -13,6 +13,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static char *FragProgFile = "CH06-brick.frag.txt";
@@ -23,23 +24,15 @@ 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} },
+   { "LightPosition",     3, GL_FLOAT, { 0.1, 0.1, 9.0, 0}, -1 },
    /* 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 } }
+   { "BrickColor",        3, GL_FLOAT, { 0.8, 0.2, 0.2, 0 }, -1 },
+   { "MortarColor",       3, GL_FLOAT, { 0.6, 0.6, 0.6, 0 }, -1 },
+   { "BrickSize",         2, GL_FLOAT, { 1.0, 0.3, 0, 0 }, -1 },
+   { "BrickPct",          2, GL_FLOAT, { 0.9, 0.8, 0, 0 }, -1 },
+   END_OF_UNIFORMS
 };
 
 static GLint win = 0;
@@ -146,121 +139,20 @@ SpecialKey(int key, int x, int y)
 
 
 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);*/
-   }
+   if (!ShadersSupported())
+      exit(1);
 
    GetExtensionFuncs();
 
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   ReadShader(vertShader, VertProgFile);
-
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   ReadShader(fragShader, FragProgFile);
+   vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
+   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
+   program = LinkShaders(vertShader, fragShader);
 
-   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();
-      }
-   }
+   InitUniforms(program, Uniforms);
 
    assert(glGetError() == 0);
 
diff --git a/progs/glsl/bump.c b/progs/glsl/bump.c
index 11f87ab127..e42421d489 100644
--- a/progs/glsl/bump.c
+++ b/progs/glsl/bump.c
@@ -13,6 +13,7 @@
 #include <GL/glu.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static char *FragProgFile = "CH11-bumpmap.frag.txt";
@@ -24,20 +25,13 @@ 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, { 10.0, 0, 0, 0 } },
-   { "BumpSize",            1, -1, { 0.125, 0, 0, 0 } },
-   { "SpecularFactor",      1, -1, { 0.5, 0, 0, 0 } },
-   { NULL, 0, 0, { 0, 0, 0, 0 } }
+   { "LightPosition",    3, GL_FLOAT, { 0.57737, 0.57735, 0.57735, 0.0 }, -1 },
+   { "SurfaceColor",     3, GL_FLOAT, { 0.8, 0.8, 0.2, 0 }, -1 },
+   { "BumpDensity",      1, GL_FLOAT, { 10.0, 0, 0, 0 }, -1 },
+   { "BumpSize",         1, GL_FLOAT, { 0.125, 0, 0, 0 }, -1 },
+   { "SpecularFactor",   1, GL_FLOAT, { 0.5, 0, 0, 0 }, -1 },
+   END_OF_UNIFORMS
 };
 
 static GLint win = 0;
@@ -232,100 +226,18 @@ SpecialKey(int key, int x, int y)
 }
 
 
-
-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, "bump: 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, "bump: Unable to open shader file %s\n", filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("bump: 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));
+   if (!ShadersSupported())
+      exit(1);
 
    GetExtensionFuncs();
 
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   ReadShader(vertShader, VertProgFile);
-
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   ReadShader(fragShader, FragProgFile);
+   vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
+   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
+   program = LinkShaders(vertShader, fragShader);
 
-   program = glCreateProgram_func();
-   glAttachShader_func(program, fragShader);
-   glAttachShader_func(program, vertShader);
-   glLinkProgram_func(program);
-   CheckLink(program);
    glUseProgram_func(program);
 
    assert(glIsProgram_func(program));
@@ -336,28 +248,7 @@ Init(void)
 
    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();
-      }
-   }
+   InitUniforms(program, Uniforms);
 
    CheckError(__LINE__);
 
diff --git a/progs/glsl/deriv.c b/progs/glsl/deriv.c
index 8b652bc1e4..e69f0b82c4 100644
--- a/progs/glsl/deriv.c
+++ b/progs/glsl/deriv.c
@@ -17,6 +17,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static char *FragProgFile = NULL;
@@ -159,68 +160,6 @@ MakeRect(void)
 }
 
 
-
-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, "fslight: problem compiling shader:\n%s\n", log);
-      exit(1);
-   }
-}
-
-
-/**
- * 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, "fslight: Unable to open shader file %s\n", filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("fslight: 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);
-   }
-}
-
-
 static void
 Init(void)
 {
@@ -234,33 +173,16 @@ Init(void)
       "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
       "   gl_TexCoord[0] = gl_MultiTexCoord0;\n"
       "}\n";
-   const char *version;
 
-   version = (const char *) glGetString(GL_VERSION);
-   if (version[0] != '2' || version[1] != '.') {
-      printf("This program requires OpenGL 2.x, found %s\n", version);
+   if (!ShadersSupported())
       exit(1);
-   }
 
    GetExtensionFuncs();
 
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   if (FragProgFile)
-      ReadShader(fragShader, FragProgFile);
-   else
-      LoadAndCompileShader(fragShader, fragShaderText);
-
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   if (VertProgFile)
-      ReadShader(vertShader, VertProgFile);
-   else
-      LoadAndCompileShader(vertShader, vertShaderText);
-
-   program = glCreateProgram_func();
-   glAttachShader_func(program, fragShader);
-   glAttachShader_func(program, vertShader);
-   glLinkProgram_func(program);
-   CheckLink(program);
+   vertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+   fragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+   program = LinkShaders(vertShader, fragShader);
+
    glUseProgram_func(program);
 
    /*assert(glGetError() == 0);*/
diff --git a/progs/glsl/mandelbrot.c b/progs/glsl/mandelbrot.c
index e7b2b04b0d..a15aad981c 100644
--- a/progs/glsl/mandelbrot.c
+++ b/progs/glsl/mandelbrot.c
@@ -13,6 +13,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static char *FragProgFile = "CH18-mandel.frag.txt";
@@ -24,28 +25,21 @@ 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 } },
+   { "LightPosition",        3, GL_FLOAT, { 0.1, 0.1, 9.0, 0}, -1 },
+   { "SpecularContribution", 1, GL_FLOAT, { 0.5, 0, 0, 0 }, -1 },
+   { "DiffuseContribution",  1, GL_FLOAT, { 0.5, 0, 0, 0 }, -1 },
+   { "Shininess",            1, GL_FLOAT, { 20.0, 0, 0, 0 }, -1 },
    /* frag */
-   { "MaxIterations",        1, -1, { 12, 0, 0, 0 } },
-   { "Zoom",                 1, -1, { 0.125, 0, 0, 0 } },
-   { "Xcenter",              1, -1, { -1.5, 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 } }
+   { "MaxIterations",        1, GL_FLOAT, { 12, 0, 0, 0 }, -1 },
+   { "Zoom",                 1, GL_FLOAT, { 0.125, 0, 0, 0 }, -1 },
+   { "Xcenter",              1, GL_FLOAT, { -1.5, 0, 0, 0 }, -1 },
+   { "Ycenter",              1, GL_FLOAT, { .005, 0, 0, 0 }, -1 },
+   { "InnerColor",           3, GL_FLOAT, { 1, 0, 0, 0 }, -1 },
+   { "OuterColor1",          3, GL_FLOAT, { 0, 1, 0, 0 }, -1 },
+   { "OuterColor2",          3, GL_FLOAT, { 0, 0, 1, 0 }, -1 },
+   END_OF_UNIFORMS
 };
 
 static GLint win = 0;
@@ -157,99 +151,20 @@ SpecialKey(int key, int x, int y)
 }
 
 
-
-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, "mandelbrot: 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, "mandelbrot: Unable to open shader file %s\n", filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("mandelbrot: 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);*/
-   }
+   if (!ShadersSupported())
+      exit(1);
 
    GetExtensionFuncs();
 
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   ReadShader(vertShader, VertProgFile);
-
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   ReadShader(fragShader, FragProgFile);
+   vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
+   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
+   program = LinkShaders(vertShader, fragShader);
 
-   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++) {
diff --git a/progs/glsl/noise.c b/progs/glsl/noise.c
index adccd1a7c8..9da71ac775 100644
--- a/progs/glsl/noise.c
+++ b/progs/glsl/noise.c
@@ -12,6 +12,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static const char *VertShaderText =
@@ -34,18 +35,11 @@ static const char *FragShaderText =
    "}\n";
 
 
-struct uniform_info {
-   const char *name;
-   GLuint size;
-   GLint location;
-   GLfloat value[4];
-};
-
 static struct uniform_info Uniforms[] = {
-   { "Scale",          4, -1, { 0.5, 0.4, 0.0, 0} },
-   { "Bias",           4, -1, { 0.5, 0.3, 0.0, 0} },
-   { "Slice",          1, -1, { 0.5, 0, 0, 0} },
-   { NULL, 0, 0, { 0, 0, 0, 0 } }
+   { "Scale",    4, GL_FLOAT, { 0.5, 0.4, 0.0, 0}, -1 },
+   { "Bias",     4, GL_FLOAT, { 0.5, 0.3, 0.0, 0}, -1 },
+   { "Slice",    1, GL_FLOAT, { 0.5, 0, 0, 0}, -1 },
+   END_OF_UNIFORMS
 };
 
 /* program/shader objects */
@@ -175,94 +169,20 @@ SpecialKey(int key, int x, int y)
 
 
 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, "noise: problem compiling shader: %s\n", log);
-      exit(1);
-   }
-   else {
-      printf("Shader compiled OK\n");
-   }
-}
-
-
-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);*/
-   }
+   if (!ShadersSupported())
+      exit(1);
 
    GetExtensionFuncs();
 
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   LoadAndCompileShader(vertShader, VertShaderText);
-
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   LoadAndCompileShader(fragShader, FragShaderText);
+   vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
+   fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
+   program = LinkShaders(vertShader, fragShader);
 
-   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();
-      }
-   }
+   InitUniforms(program, Uniforms);
 
    assert(glGetError() == 0);
 
diff --git a/progs/glsl/points.c b/progs/glsl/points.c
index 85115de504..392dc4db85 100644
--- a/progs/glsl/points.c
+++ b/progs/glsl/points.c
@@ -14,6 +14,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static GLuint FragShader;
@@ -182,40 +183,6 @@ SpecialKey(int key, int x, int y)
 
 
 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, "fslight: problem compiling shader:\n%s\n", log);
-      exit(1);
-   }
-}
-
-
-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);
-   }
-}
-
-
-static void
 Init(void)
 {
    /* Fragment shader: compute distance of fragment from center of point
@@ -254,28 +221,16 @@ Init(void)
       "   gl_TexCoord[0] = gl_MultiTexCoord0; \n"
       "   gl_FrontColor = gl_Color; \n"
       "}\n";
-   const char *version;
 
-   version = (const char *) glGetString(GL_VERSION);
-   if (version[0] != '2' || version[1] != '.') {
-      printf("This program requires OpenGL 2.x, found %s\n", version);
+   if (!ShadersSupported())
       exit(1);
-   }
-   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 
    GetExtensionFuncs();
 
-   FragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   LoadAndCompileShader(FragShader, fragShaderText);
-
-   VertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   LoadAndCompileShader(VertShader, vertShaderText);
+   VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+   FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+   Program = LinkShaders(VertShader, FragShader);
 
-   Program = glCreateProgram_func();
-   glAttachShader_func(Program, FragShader);
-   glAttachShader_func(Program, VertShader);
-   glLinkProgram_func(Program);
-   CheckLink(Program);
    glUseProgram_func(Program);
 
    uViewportInv = glGetUniformLocation_func(Program, "viewportInv");
diff --git a/progs/glsl/texdemo1.c b/progs/glsl/texdemo1.c
index d29ecf452b..3dd19eaf4b 100644
--- a/progs/glsl/texdemo1.c
+++ b/progs/glsl/texdemo1.c
@@ -31,6 +31,7 @@
 #include "GL/glut.h"
 #include "readtex.h"
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 static const char *Demo = "texdemo1";
 
@@ -50,39 +51,20 @@ static GLfloat EyeDist = 10;
 static GLboolean Anim = GL_TRUE;
 
 
-struct uniform_info {
-   const char *name;
-   GLuint size;
-   GLint location;
-   GLenum type;  /**< GL_FLOAT or GL_INT */
-   GLfloat value[4];
-};
-
 static struct uniform_info ReflectUniforms[] = {
-   { "cubeTex",  1, -1, GL_INT, { 0, 0, 0, 0 } },
-   { "lightPos", 3, -1, GL_FLOAT, { 10, 10, 20, 0 } },
-   { NULL, 0, 0, 0, { 0, 0, 0, 0 } }
+   { "cubeTex",  1, GL_INT, { 0, 0, 0, 0 }, -1 },
+   { "lightPos", 3, GL_FLOAT, { 10, 10, 20, 0 }, -1 },
+   END_OF_UNIFORMS
 };
 
 static struct uniform_info SimpleUniforms[] = {
-   { "tex2d",    1, -1, GL_INT,   { 1, 0, 0, 0 } },
-   { "lightPos", 3, -1, GL_FLOAT, { 10, 10, 20, 0 } },
-   { NULL, 0, 0, 0, { 0, 0, 0, 0 } }
+   { "tex2d",    1, GL_INT,   { 1, 0, 0, 0 }, -1 },
+   { "lightPos", 3, GL_FLOAT, { 10, 10, 20, 0 }, -1 },
+   END_OF_UNIFORMS
 };
 
 
 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);
-   }
-}
-
-
-static void
 DrawGround(GLfloat size)
 {
    glPushMatrix();
@@ -386,132 +368,19 @@ InitTextures(GLboolean useImageFiles)
 }
 
 
-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, "%s: problem compiling shader: %s\n", Demo, 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, "%s: Unable to open shader file %s\n", Demo, filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("%s: read %d bytes from shader file %s\n", Demo, 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 GLuint
 CreateProgram(const char *vertProgFile, const char *fragProgFile,
               struct uniform_info *uniforms)
 {
-   GLuint fragShader = 0, vertShader = 0, program = 0;
-   GLint i;
-
-   program = glCreateProgram_func();
-   if (vertProgFile) {
-      vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-      ReadShader(vertShader, vertProgFile);
-      glAttachShader_func(program, vertShader);
-   }
+   GLuint fragShader, vertShader, program;
 
-   if (fragProgFile) {
-      fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-      ReadShader(fragShader, fragProgFile);
-      glAttachShader_func(program, fragShader);
-   }
-
-   glLinkProgram_func(program);
-   CheckLink(program);
+   vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
+   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
+   program = LinkShaders(vertShader, fragShader);
 
    glUseProgram_func(program);
 
-   assert(glIsProgram_func(program));
-   assert(glIsShader_func(fragShader));
-   assert(glIsShader_func(vertShader));
-
-   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:
-         if (uniforms[i].type == GL_INT)
-            glUniform1i_func(uniforms[i].location,
-                             (GLint) uniforms[i].value[0]);
-         else
-            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__);
+   InitUniforms(program, uniforms);
 
    return program;
 }
diff --git a/progs/glsl/toyball.c b/progs/glsl/toyball.c
index 3aa096161a..b870435f66 100644
--- a/progs/glsl/toyball.c
+++ b/progs/glsl/toyball.c
@@ -13,6 +13,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static char *FragProgFile = "CH11-toyball.frag.txt";
@@ -24,30 +25,23 @@ 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 } }
+   { "LightDir",       4, GL_FLOAT, { 0.57737, 0.57735, 0.57735, 0.0 }, -1 },
+   { "HVector",        4, GL_FLOAT, { 0.32506, 0.32506, 0.88808, 0.0 }, -1 },
+   { "BallCenter",     4, GL_FLOAT, { 0.0, 0.0, 0.0, 1.0 }, -1 },
+   { "SpecularColor",  4, GL_FLOAT, { 0.4, 0.4, 0.4, 60.0 }, -1 },
+   { "Red",         4, GL_FLOAT, { 0.6, 0.0, 0.0, 1.0 }, -1 },
+   { "Blue",        4, GL_FLOAT, { 0.0, 0.3, 0.6, 1.0 }, -1 },
+   { "Yellow",      4, GL_FLOAT, { 0.6, 0.5, 0.0, 1.0 }, -1 },
+   { "HalfSpace0",  4, GL_FLOAT, { 1.0, 0.0, 0.0, 0.2 }, -1 },
+   { "HalfSpace1",  4, GL_FLOAT, { 0.309016994, 0.951056516, 0.0, 0.2 }, -1 },
+   { "HalfSpace2",  4, GL_FLOAT, { -0.809016994, 0.587785252, 0.0, 0.2 }, -1 },
+   { "HalfSpace3",  4, GL_FLOAT, { -0.809016994, -0.587785252, 0.0, 0.2 }, -1 },
+   { "HalfSpace4",  4, GL_FLOAT, { 0.309116994, -0.951056516, 0.0, 0.2 }, -1 },
+   { "InOrOutInit", 1, GL_FLOAT, { -3.0, 0, 0, 0 }, -1 },
+   { "StripeWidth", 1, GL_FLOAT, {  0.3, 0, 0, 0 }, -1 },
+   { "FWidth",      1, GL_FLOAT, { 0.005, 0, 0, 0 }, -1 },
+   END_OF_UNIFORMS
 };
 
 static GLint win = 0;
@@ -172,127 +166,20 @@ SpecialKey(int key, int x, int y)
 
 
 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, "toyball: 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, "toyball: Unable to open shader file %s\n", filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("toyball: 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));
+   if (!ShadersSupported())
+      exit(1);
 
    GetExtensionFuncs();
 
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   ReadShader(vertShader, VertProgFile);
-
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   ReadShader(fragShader, FragProgFile);
+   vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
+   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
+   program = LinkShaders(vertShader, fragShader);
 
-   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();
-      }
-   }
+   InitUniforms(program, Uniforms);
 
    assert(glGetError() == 0);
 
diff --git a/progs/glsl/trirast.c b/progs/glsl/trirast.c
index 2842755447..67cbac0546 100644
--- a/progs/glsl/trirast.c
+++ b/progs/glsl/trirast.c
@@ -19,6 +19,7 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static GLint WinWidth = 300, WinHeight = 300;
@@ -169,67 +170,6 @@ Key(unsigned char key, int x, int y)
 
 
 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, "fslight: problem compiling shader:\n%s\n", log);
-      exit(1);
-   }
-}
-
-
-/**
- * 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, "fslight: Unable to open shader file %s\n", filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("fslight: 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);
-   }
-}
-
-
-static void
 Init(void)
 {
    static const char *fragShaderText =
@@ -252,33 +192,16 @@ Init(void)
       "void main() {\n"
       "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
       "}\n";
-   const char *version;
 
-   version = (const char *) glGetString(GL_VERSION);
-   if (version[0] != '2' || version[1] != '.') {
-      printf("This program requires OpenGL 2.x, found %s\n", version);
+   if (!ShadersSupported())
       exit(1);
-   }
 
    GetExtensionFuncs();
 
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   if (FragProgFile)
-      ReadShader(fragShader, FragProgFile);
-   else
-      LoadAndCompileShader(fragShader, fragShaderText);
-
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   if (VertProgFile)
-      ReadShader(vertShader, VertProgFile);
-   else
-      LoadAndCompileShader(vertShader, vertShaderText);
+   vertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+   fragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+   program = LinkShaders(vertShader, fragShader);
 
-   program = glCreateProgram_func();
-   glAttachShader_func(program, fragShader);
-   glAttachShader_func(program, vertShader);
-   glLinkProgram_func(program);
-   CheckLink(program);
    glUseProgram_func(program);
 
    uv0 = glGetUniformLocation_func(program, "v0");
diff --git a/progs/glsl/twoside.c b/progs/glsl/twoside.c
index 1db92b5512..77977be536 100644
--- a/progs/glsl/twoside.c
+++ b/progs/glsl/twoside.c
@@ -16,9 +16,9 @@
 #include <GL/glut.h>
 #include <GL/glext.h>
 #include "extfuncs.h"
+#include "shaderutil.h"
 
 
-static const char *Prog = "twoside";
 static GLint WinWidth = 300, WinHeight = 300;
 static char *FragProgFile = NULL;
 static char *VertProgFile = NULL;
@@ -168,67 +168,6 @@ Key(unsigned char key, int x, int y)
 
 
 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, "%s: problem compiling shader:\n%s\n", Prog, log);
-      exit(1);
-   }
-}
-
-
-/**
- * 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, "%s: Unable to open shader file %s\n", Prog, filename);
-      exit(1);
-   }
-
-   n = fread(buffer, 1, max, f);
-   printf("%s: read %d bytes from shader file %s\n", Prog, 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);
-   }
-}
-
-
-static void
 Init(void)
 {
    static const char *fragShaderText =
@@ -255,33 +194,16 @@ Init(void)
       "   } \n"
       "   gl_Position = ftransform(); \n"
       "} \n";
-   const char *version;
 
-   version = (const char *) glGetString(GL_VERSION);
-   if (version[0] != '2' || version[1] != '.') {
-      printf("This program requires OpenGL 2.x, found %s\n", version);
+   if (!ShadersSupported())
       exit(1);
-   }
 
    GetExtensionFuncs();
 
-   fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   if (FragProgFile)
-      ReadShader(fragShader, FragProgFile);
-   else
-      LoadAndCompileShader(fragShader, fragShaderText);
-
-   vertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   if (VertProgFile)
-      ReadShader(vertShader, VertProgFile);
-   else
-      LoadAndCompileShader(vertShader, vertShaderText);
-
-   program = glCreateProgram_func();
-   glAttachShader_func(program, fragShader);
-   glAttachShader_func(program, vertShader);
-   glLinkProgram_func(program);
-   CheckLink(program);
+   vertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+   fragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+   program = LinkShaders(vertShader, fragShader);
+
    glUseProgram_func(program);
 
    u_fragface = glGetUniformLocation_func(program, "fragface");