demos: added progs/glsl/linktest.c to test linking of separate compilation units

2 files changed, 265 insertions, 0 deletions

diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile
index 8061277033..0f1a299570 100644
--- a/progs/glsl/Makefile
+++ b/progs/glsl/Makefile
@@ -17,6 +17,7 @@ PROGS = \
 	deriv \
 	identity \
 	fragcoord \
+	linktest \
 	mandelbrot \
 	multinoise \
 	multitex \
@@ -128,6 +129,12 @@ fragcoord: fragcoord.o shaderutil.o
 	$(APP_CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) fragcoord.o shaderutil.o $(LIBS) -o $@
 
 
+linktest.o: linktest.c extfuncs.h shaderutil.h
+	$(APP_CC) -c -I$(INCDIR) $(CFLAGS) linktest.c
+
+linktest: linktest.o shaderutil.o
+	$(APP_CC) -I$(INCDIR) $(CFLAGS) $(LDFLAGS) linktest.o shaderutil.o $(LIBS) -o $@
+
 mandelbrot.o: mandelbrot.c extfuncs.h shaderutil.h
 	$(APP_CC) -c -I$(INCDIR) $(CFLAGS) mandelbrot.c
 
diff --git a/progs/glsl/linktest.c b/progs/glsl/linktest.c
new file mode 100644
index 0000000000..601b24e893
--- /dev/null
+++ b/progs/glsl/linktest.c
@@ -0,0 +1,258 @@
+/**
+ * Test linking of multiple compilation units.
+ * Brian Paul
+ * 28 March 2009
+ */
+
+#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"
+#include "shaderutil.h"
+
+
+static GLfloat diffuse[4] = { 0.5f, 1.0f, 0.5f, 1.0f };
+static GLfloat specular[4] = { 0.8f, 0.8f, 0.8f, 1.0f };
+static GLfloat lightPos[4] = { 0.0f, 10.0f, 20.0f, 0.0f };
+static GLfloat delta = 1.0f;
+
+static GLuint VertShader1;
+static GLuint VertShader2;
+static GLuint FragShader1;
+static GLuint FragShader2;
+static GLuint Program;
+
+static GLint uDiffuse;
+static GLint uSpecular;
+static GLint uTexture;
+
+static GLint Win = 0;
+static GLboolean anim = GL_TRUE;
+
+
+
+static const char *FragShaderSource1 =
+   "float compute_dotprod(const vec3 normal) \n"
+   "{ \n"
+   "   float dotProd = max(dot(gl_LightSource[0].position.xyz, \n"
+   "                           normalize(normal)), 0.0); \n"
+   "   return dotProd; \n"
+   "} \n";
+
+static const char *FragShaderSource2 =
+   "uniform vec4 diffuse;\n"
+   "uniform vec4 specular;\n"
+   "varying vec3 normal;\n"
+   "\n"
+   "// external function \n"
+   "float compute_dotprod(const vec3 normal); \n"
+   "\n"
+   "void main() \n"
+   "{ \n"
+   "   float dotProd = compute_dotprod(normal); \n"
+   "   gl_FragColor = diffuse * dotProd + specular * pow(dotProd, 20.0); \n"
+   "} \n";
+
+
+static const char *VertShaderSource1 =
+   "vec3 compute_normal() \n"
+   "{ \n"
+   "   return gl_NormalMatrix * gl_Normal; \n"
+   "} \n";
+
+static const char *VertShaderSource2 =
+   "varying vec3 normal;\n"
+   "\n"
+   "// external function \n"
+   "vec3 compute_normal(); \n"
+   "\n"
+   "void main() \n"
+   "{ \n"
+   "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; \n"
+   "   normal = compute_normal(); \n"
+   "} \n";
+
+
+static void
+normalize(GLfloat *dst, const GLfloat *src)
+{
+   GLfloat len = sqrt(src[0] * src[0] + src[1] * src[1] + src[2] * src[2]);
+   dst[0] = src[0] / len;
+   dst[1] = src[1] / len;
+   dst[2] = src[2] / len;
+   dst[3] = src[3];
+}
+
+
+static void
+Redisplay(void)
+{
+   GLfloat vec[4];
+
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+   /* update light position */
+   normalize(vec, lightPos);
+   glLightfv(GL_LIGHT0, GL_POSITION, vec);
+   
+   glutSolidSphere(2.0, 10, 5);
+
+   glutSwapBuffers();
+}
+
+
+static void
+Idle(void)
+{
+   lightPos[0] += delta;
+   if (lightPos[0] > 25.0f || lightPos[0] < -25.0f)
+      delta = -delta;
+   glutPostRedisplay();
+}
+
+
+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(VertShader1);
+   glDeleteShader_func(VertShader2);
+   glDeleteShader_func(FragShader1);
+   glDeleteShader_func(FragShader2);
+   glDeleteProgram_func(Program);
+   glutDestroyWindow(Win);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+  (void) x;
+  (void) y;
+
+   switch(key) {
+   case ' ':
+   case 'a':
+      anim = !anim;
+      if (anim)
+         glutIdleFunc(Idle);
+      else
+         glutIdleFunc(NULL);
+      break;
+   case 'x':
+      lightPos[0] -= 1.0f;
+      break;
+   case 'X':
+      lightPos[0] += 1.0f;
+      break;
+   case 27:
+      CleanUp();
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+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)
+{
+   if (!ShadersSupported())
+      exit(1);
+
+   GetExtensionFuncs();
+
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   VertShader1 = CompileShaderText(GL_VERTEX_SHADER, VertShaderSource1);
+   VertShader2 = CompileShaderText(GL_VERTEX_SHADER, VertShaderSource2);
+   FragShader1 = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderSource1);
+   FragShader2 = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderSource2);
+
+   Program = glCreateProgram_func();
+   glAttachShader_func(Program, VertShader1);
+   glAttachShader_func(Program, VertShader2);
+   glAttachShader_func(Program, FragShader1);
+   glAttachShader_func(Program, FragShader2);
+
+   glLinkProgram_func(Program);
+
+   CheckLink(Program);
+
+   glUseProgram_func(Program);
+
+   uDiffuse = glGetUniformLocation_func(Program, "diffuse");
+   uSpecular = glGetUniformLocation_func(Program, "specular");
+   uTexture = glGetUniformLocation_func(Program, "texture");
+   printf("DiffusePos %d  SpecularPos %d  TexturePos %d\n",
+          uDiffuse, uSpecular, uTexture);
+
+   glUniform4fv_func(uDiffuse, 1, diffuse);
+   glUniform4fv_func(uSpecular, 1, specular);
+
+   glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
+   glEnable(GL_DEPTH_TEST);
+
+   glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
+   glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
+   glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 10.0f);
+
+   assert(glIsProgram_func(Program));
+   assert(glIsShader_func(VertShader1));
+   assert(glIsShader_func(VertShader2));
+   assert(glIsShader_func(FragShader1));
+   assert(glIsShader_func(FragShader2));
+
+   glColor3f(1, 0, 0);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowPosition( 0, 0);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+   Win = glutCreateWindow(argv[0]);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(Key);
+   glutDisplayFunc(Redisplay);
+   if (anim)
+      glutIdleFunc(Idle);
+   Init();
+   glutMainLoop();
+   return 0;
+}
+
+