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/**
* Test OpenGL 2.0 vertex/fragment shaders.
* Brian Paul
* 1 November 2006
*
* Based on ARB version by:
* Michal Krol
* 20 February 2006
*
* Based on the original demo by:
* Brian Paul
* 17 April 2003
*/
#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"
#define TEXTURE 0
static GLint CoordAttrib = 0;
static char *FragProgFile = NULL;
static char *VertProgFile = NULL;
static GLfloat diffuse[4] = { 0.5f, 0.5f, 1.0f, 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 fragShader;
static GLuint vertShader;
static GLuint program;
static GLint uDiffuse;
static GLint uSpecular;
static GLint uTexture;
static GLuint SphereList, RectList, CurList;
static GLint win = 0;
static GLboolean anim = 0*GL_TRUE;
static GLboolean wire = GL_FALSE;
static GLboolean pixelLight = GL_TRUE;
static GLint t0 = 0;
static GLint frames = 0;
static GLfloat xRot = 90.0f, yRot = 0.0f;
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);
if (pixelLight) {
glUseProgram_func(program);
glDisable(GL_LIGHTING);
}
else {
glUseProgram_func(0);
glEnable(GL_LIGHTING);
}
glPushMatrix();
glRotatef(xRot, 1.0f, 0.0f, 0.0f);
glRotatef(yRot, 0.0f, 1.0f, 0.0f);
/*
glutSolidSphere(2.0, 10, 5);
*/
glCallList(CurList);
glPopMatrix();
glutSwapBuffers();
frames++;
if (anim) {
GLint t = glutGet(GLUT_ELAPSED_TIME);
if (t - t0 >= 5000) {
GLfloat seconds =(GLfloat)(t - t0) / 1000.0f;
GLfloat fps = frames / seconds;
printf("%d frames in %6.3f seconds = %6.3f FPS\n",
frames, seconds, fps);
t0 = t;
frames = 0;
}
}
}
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(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 ' ':
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 'w':
wire = !wire;
if (wire)
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
else
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
break;
case 'o':
if (CurList == SphereList)
CurList = RectList;
else
CurList = SphereList;
break;
case 'p':
pixelLight = !pixelLight;
if (pixelLight)
printf("Per-pixel lighting\n");
else
printf("Conventional lighting\n");
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
TestFunctions(void)
{
printf("Error 0x%x at line %d\n", glGetError(), __LINE__);
assert(glIsProgram_func(program));
assert(glIsShader_func(fragShader));
assert(glIsShader_func(vertShader));
/* attached shaders */
{
GLuint shaders[20];
GLsizei count;
int i;
glGetAttachedShaders_func(program, 20, &count, shaders);
for (i = 0; i < count; i++) {
printf("Attached: %u\n", shaders[i]);
assert(shaders[i] == fragShader ||
shaders[i] == vertShader);
}
}
{
GLchar log[1000];
GLsizei len;
glGetShaderInfoLog_func(vertShader, 1000, &len, log);
printf("Vert Shader Info Log: %s\n", log);
glGetShaderInfoLog_func(fragShader, 1000, &len, log);
printf("Frag Shader Info Log: %s\n", log);
glGetProgramInfoLog_func(program, 1000, &len, log);
printf("Program Info Log: %s\n", log);
}
/* active uniforms */
{
GLint n, max, i;
glGetProgramiv_func(program, GL_ACTIVE_UNIFORMS, &n);
glGetProgramiv_func(program, GL_ACTIVE_UNIFORM_MAX_LENGTH, &max);
printf("Num uniforms: %d Max name length: %d\n", n, max);
for (i = 0; i < n; i++) {
GLint size, len;
GLenum type;
char name[100];
glGetActiveUniform_func(program, i, 100, &len, &size, &type, name);
printf(" %d: %s nameLen=%d size=%d type=0x%x\n",
i, name, len, size, type);
}
}
}
#if TEXTURE
static void
MakeTexture(void)
{
#define SZ0 64
#define SZ1 32
GLubyte image0[SZ0][SZ0][SZ0][4];
GLubyte image1[SZ1][SZ1][SZ1][4];
GLuint i, j, k;
/* level 0: two-tone gray checkboard */
for (i = 0; i < SZ0; i++) {
for (j = 0; j < SZ0; j++) {
for (k = 0; k < SZ0; k++) {
if ((i/8 + j/8 + k/8) & 1) {
image0[i][j][k][0] =
image0[i][j][k][1] =
image0[i][j][k][2] = 200;
}
else {
image0[i][j][k][0] =
image0[i][j][k][1] =
image0[i][j][k][2] = 100;
}
image0[i][j][k][3] = 255;
}
}
}
/* level 1: two-tone green checkboard */
for (i = 0; i < SZ1; i++) {
for (j = 0; j < SZ1; j++) {
for (k = 0; k < SZ1; k++) {
if ((i/8 + j/8 + k/8) & 1) {
image1[i][j][k][0] = 0;
image1[i][j][k][1] = 250;
image1[i][j][k][2] = 0;
}
else {
image1[i][j][k][0] = 0;
image1[i][j][k][1] = 200;
image1[i][j][k][2] = 0;
}
image1[i][j][k][3] = 255;
}
}
}
glActiveTexture(GL_TEXTURE2); /* unit 2 */
glBindTexture(GL_TEXTURE_2D, 42);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SZ0, SZ0, 0,
GL_RGBA, GL_UNSIGNED_BYTE, image0);
glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, SZ1, SZ1, 0,
GL_RGBA, GL_UNSIGNED_BYTE, image1);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glActiveTexture(GL_TEXTURE4); /* unit 4 */
glBindTexture(GL_TEXTURE_3D, 43);
glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, SZ0, SZ0, SZ0, 0,
GL_RGBA, GL_UNSIGNED_BYTE, image0);
glTexImage3D(GL_TEXTURE_3D, 1, GL_RGBA, SZ1, SZ1, SZ1, 0,
GL_RGBA, GL_UNSIGNED_BYTE, image1);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAX_LEVEL, 1);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}
#endif
static void
MakeSphere(void)
{
GLUquadricObj *obj = gluNewQuadric();
SphereList = glGenLists(1);
gluQuadricTexture(obj, GL_TRUE);
glNewList(SphereList, GL_COMPILE);
gluSphere(obj, 2.0f, 10, 5);
glEndList();
}
static void
VertAttrib(GLint index, float x, float y)
{
#if 1
glVertexAttrib2f_func(index, x, y);
#else
glTexCoord2f(x, y);
#endif
}
static void
MakeRect(void)
{
RectList = glGenLists(1);
glNewList(RectList, GL_COMPILE);
glNormal3f(0, 0, 1);
glBegin(GL_POLYGON);
VertAttrib(CoordAttrib, 0, 0); glVertex2f(-2, -2);
VertAttrib(CoordAttrib, 1, 0); glVertex2f( 2, -2);
VertAttrib(CoordAttrib, 1, 1); glVertex2f( 2, 2);
VertAttrib(CoordAttrib, 0, 1); glVertex2f(-2, 2);
glEnd(); /* XXX omit this and crash! */
glEndList();
}
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 =
"uniform vec4 diffuse;\n"
"uniform vec4 specular;\n"
"varying vec3 normal;\n"
"void main() {\n"
" // Compute dot product of light direction and normal vector\n"
" float dotProd = max(dot(gl_LightSource[0].position.xyz, \n"
" normalize(normal)), 0.0);\n"
" // Compute diffuse and specular contributions\n"
" gl_FragColor = diffuse * dotProd + specular * pow(dotProd, 20.0);\n"
"}\n";
static const char *vertShaderText =
"varying vec3 normal;\n"
"void main() {\n"
" gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
" normal = gl_NormalMatrix * gl_Normal;\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);
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);
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);
/* assert(glGetError() == 0);*/
#if TEXTURE
glUniform1i_func(uTexture, 2); /* use texture unit 2 */
#endif
/*assert(glGetError() == 0);*/
if (CoordAttrib) {
int i;
glBindAttribLocation_func(program, CoordAttrib, "coord");
i = glGetAttribLocation_func(program, "coord");
assert(i >= 0);
if (i != CoordAttrib) {
printf("Hmmm, NVIDIA bug?\n");
CoordAttrib = i;
}
else {
printf("Mesa bind attrib: coord = %d\n", i);
}
}
/*assert(glGetError() == 0);*/
glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHT0);
glEnable(GL_LIGHTING);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 20.0f);
MakeSphere();
MakeRect();
CurList = SphereList;
#if TEXTURE
MakeTexture();
#endif
printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
printf("Press p to toggle between per-pixel and per-vertex lighting\n");
/* test glGetShaderSource() */
if (0) {
GLsizei len = strlen(fragShaderText) + 1;
GLsizei lenOut;
GLchar *src =(GLchar *) malloc(len * sizeof(GLchar));
glGetShaderSource_func(fragShader, 0, NULL, src);
glGetShaderSource_func(fragShader, len, &lenOut, src);
assert(len == lenOut + 1);
assert(strcmp(src, fragShaderText) == 0);
free(src);
}
assert(glIsProgram_func(program));
assert(glIsShader_func(fragShader));
assert(glIsShader_func(vertShader));
glColor3f(1, 0, 0);
/* for testing state vars */
{
static GLfloat fc[4] = { 1, 1, 0, 0 };
static GLfloat amb[4] = { 1, 0, 1, 0 };
glFogfv(GL_FOG_COLOR, fc);
glLightfv(GL_LIGHT1, GL_AMBIENT, amb);
}
#if 0
TestFunctions();
#else
(void) TestFunctions;
#endif
}
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(200, 200);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
win = glutCreateWindow(argv[0]);
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutSpecialFunc(SpecialKey);
glutDisplayFunc(Redisplay);
if (anim)
glutIdleFunc(Idle);
ParseOptions(argc, argv);
Init();
glutMainLoop();
return 0;
}
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