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/**
* 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/glew.h>
#include <GL/glut.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(VertShader1);
glDeleteShader(VertShader2);
glDeleteShader(FragShader1);
glDeleteShader(FragShader2);
glDeleteProgram(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(prog, GL_LINK_STATUS, &stat);
if (!stat) {
GLchar log[1000];
GLsizei len;
glGetProgramInfoLog(prog, 1000, &len, log);
fprintf(stderr, "Linker error:\n%s\n", log);
}
}
static void
Init(void)
{
if (!ShadersSupported())
exit(1);
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();
glAttachShader(Program, VertShader1);
glAttachShader(Program, VertShader2);
glAttachShader(Program, FragShader1);
glAttachShader(Program, FragShader2);
glLinkProgram(Program);
CheckLink(Program);
glUseProgram(Program);
uDiffuse = glGetUniformLocation(Program, "diffuse");
uSpecular = glGetUniformLocation(Program, "specular");
uTexture = glGetUniformLocation(Program, "texture");
printf("DiffusePos %d SpecularPos %d TexturePos %d\n",
uDiffuse, uSpecular, uTexture);
glUniform4fv(uDiffuse, 1, diffuse);
glUniform4fv(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(Program));
assert(glIsShader(VertShader1));
assert(glIsShader(VertShader2));
assert(glIsShader(FragShader1));
assert(glIsShader(FragShader2));
glColor3f(1, 0, 0);
}
int
main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitWindowSize(300, 300);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
Win = glutCreateWindow(argv[0]);
glewInit();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutDisplayFunc(Redisplay);
if (anim)
glutIdleFunc(Idle);
Init();
glutMainLoop();
return 0;
}
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