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/*
* Specular reflection demo. The specular highlight is modulated by
* a sphere-mapped texture. The result is a high-gloss surface.
* NOTE: you really need hardware acceleration for this.
* Also note, this technique can't be implemented with multi-texture
* and separate specular color interpolation because there's no way
* to indicate that the second texture unit (the reflection map)
* should modulate the specular color and not the base color.
* A future multi-texture extension could fix that.
*
* Command line options:
* -info print GL implementation information
*
*
* Brian Paul October 22, 1999 This program is in the public domain.
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <GL/glew.h>
#include <GL/glut.h>
#include "readtex.h"
#include "trackball.h"
#define SPECULAR_TEXTURE_FILE "../images/reflect.rgb"
#define BASE_TEXTURE_FILE "../images/tile.rgb"
/* Menu items */
#define DO_SPEC_TEXTURE 1
#define OBJECT 2
#define ANIMATE 3
#define QUIT 100
/* for convolution */
#define FILTER_SIZE 7
static GLint WinWidth = 500, WinHeight = 500;
static GLuint CylinderObj = 0;
static GLuint TeapotObj = 0;
static GLuint Object = 0;
static GLboolean Animate = GL_TRUE;
static float CurQuat[4] = { 0, 0, 0, 1 };
static GLfloat Black[4] = { 0, 0, 0, 0 };
static GLfloat White[4] = { 1, 1, 1, 1 };
static GLfloat Diffuse[4] = { .3, .3, 1.0, 1.0 }; /* blue */
static GLfloat Shininess = 6;
static GLuint BaseTexture, SpecularTexture;
static GLboolean DoSpecTexture = GL_TRUE;
static GLboolean ButtonDown = GL_FALSE;
static GLint ButtonX, ButtonY;
/* performance info */
static GLint T0 = 0;
static GLint Frames = 0;
static void Idle( void )
{
static const float yAxis[3] = {0, 1, 0};
static double t0 = -1.;
float quat[4];
double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
if (t0 < 0.0)
t0 = t;
dt = t - t0;
t0 = t;
axis_to_quat(yAxis, 2.0 * dt, quat);
add_quats(quat, CurQuat, CurQuat);
glutPostRedisplay();
}
static void Display( void )
{
GLfloat rot[4][4];
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glPushMatrix();
build_rotmatrix(rot, CurQuat);
glMultMatrixf(&rot[0][0]);
/* First pass: diffuse lighting with base texture */
glMaterialfv(GL_FRONT, GL_DIFFUSE, Diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, Black);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, BaseTexture);
glCallList(Object);
/* Second pass: specular lighting with reflection texture */
glEnable(GL_POLYGON_OFFSET_FILL);
glBlendFunc(GL_ONE, GL_ONE); /* add */
glEnable(GL_BLEND);
glMaterialfv(GL_FRONT, GL_DIFFUSE, Black);
glMaterialfv(GL_FRONT, GL_SPECULAR, White);
if (DoSpecTexture) {
glBindTexture(GL_TEXTURE_2D, SpecularTexture);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
}
else {
glDisable(GL_TEXTURE_2D);
}
glCallList(Object);
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glDisable(GL_BLEND);
glDisable(GL_POLYGON_OFFSET_FILL);
glPopMatrix();
glutSwapBuffers();
if (Animate) {
GLint t = glutGet(GLUT_ELAPSED_TIME);
Frames++;
if (t - T0 >= 5000) {
GLfloat seconds = (t - T0) / 1000.0;
GLfloat fps = Frames / seconds;
printf("%d frames in %g seconds = %g FPS\n", Frames, seconds, fps);
fflush(stdout);
T0 = t;
Frames = 0;
}
}
}
static void Reshape( int width, int height )
{
GLfloat h = 30.0;
GLfloat w = h * width / height;
WinWidth = width;
WinHeight = height;
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glFrustum( -w, w, -h, h, 150.0, 500.0 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glTranslatef( 0.0, 0.0, -380.0 );
}
static void ToggleAnimate(void)
{
Animate = !Animate;
if (Animate) {
glutIdleFunc( Idle );
T0 = glutGet(GLUT_ELAPSED_TIME);
Frames = 0;
}
else {
glutIdleFunc( NULL );
}
}
static void ModeMenu(int entry)
{
if (entry==ANIMATE) {
ToggleAnimate();
}
else if (entry==DO_SPEC_TEXTURE) {
DoSpecTexture = !DoSpecTexture;
}
else if (entry==OBJECT) {
if (Object == TeapotObj)
Object = CylinderObj;
else
Object = TeapotObj;
}
else if (entry==QUIT) {
exit(0);
}
glutPostRedisplay();
}
static void Key( unsigned char key, int x, int y )
{
(void) x;
(void) y;
switch (key) {
case 's':
Shininess--;
if (Shininess < 0.0)
Shininess = 0.0;
glMaterialf(GL_FRONT, GL_SHININESS, Shininess);
printf("Shininess = %g\n", Shininess);
break;
case 'S':
Shininess++;
if (Shininess > 128.0)
Shininess = 128.0;
glMaterialf(GL_FRONT, GL_SHININESS, Shininess);
printf("Shininess = %g\n", Shininess);
break;
case 'a':
case ' ':
ToggleAnimate();
break;
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void
MouseMotion(int x, int y)
{
if (ButtonDown) {
float x0 = (2.0 * ButtonX - WinWidth) / WinWidth;
float y0 = (WinHeight - 2.0 * ButtonY) / WinHeight;
float x1 = (2.0 * x - WinWidth) / WinWidth;
float y1 = (WinHeight - 2.0 * y) / WinHeight;
float q[4];
trackball(q, x0, y0, x1, y1);
ButtonX = x;
ButtonY = y;
add_quats(q, CurQuat, CurQuat);
glutPostRedisplay();
}
}
static void
MouseButton(int button, int state, int x, int y)
{
if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) {
ButtonDown = GL_TRUE;
ButtonX = x;
ButtonY = y;
}
else if (button == GLUT_LEFT_BUTTON && state == GLUT_UP) {
ButtonDown = GL_FALSE;
}
}
static void Init( int argc, char *argv[] )
{
GLboolean convolve = GL_FALSE;
GLboolean fullscreen = GL_FALSE;
int i;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-info")==0) {
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
printf("GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
}
else if (strcmp(argv[i], "-c")==0) {
convolve = GL_TRUE;
}
else if (strcmp(argv[i], "-f")==0) {
fullscreen = GL_TRUE;
}
}
if (fullscreen)
glutFullScreen();
/* Cylinder object */
{
static GLfloat height = 100.0;
static GLfloat radius = 40.0;
static GLint slices = 24; /* pie slices around Z axis */
static GLint stacks = 10; /* subdivisions along length of cylinder */
static GLint rings = 4; /* rings in the end disks */
GLUquadricObj *q = gluNewQuadric();
assert(q);
gluQuadricTexture(q, GL_TRUE);
CylinderObj = glGenLists(1);
glNewList(CylinderObj, GL_COMPILE);
glPushMatrix();
glTranslatef(0.0, 0.0, -0.5 * height);
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
/*glScalef(8.0, 4.0, 2.0);*/
glMatrixMode(GL_MODELVIEW);
/* cylinder */
gluQuadricNormals(q, GL_SMOOTH);
gluQuadricTexture(q, GL_TRUE);
gluCylinder(q, radius, radius, height, slices, stacks);
/* end cap */
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glScalef(3.0, 3.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glTranslatef(0.0, 0.0, height);
gluDisk(q, 0.0, radius, slices, rings);
/* other end cap */
glTranslatef(0.0, 0.0, -height);
gluQuadricOrientation(q, GLU_INSIDE);
gluDisk(q, 0.0, radius, slices, rings);
glPopMatrix();
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glEndList();
gluDeleteQuadric(q);
}
/* Teapot */
{
TeapotObj = glGenLists(1);
glNewList(TeapotObj, GL_COMPILE);
glFrontFace(GL_CW);
glutSolidTeapot(40.0);
glFrontFace(GL_CCW);
glEndList();
}
/* show cylinder by default */
Object = CylinderObj;
/* lighting */
glEnable(GL_LIGHTING);
{
GLfloat pos[4] = { 3, 3, 3, 1 };
glLightfv(GL_LIGHT0, GL_AMBIENT, Black);
glLightfv(GL_LIGHT0, GL_DIFFUSE, White);
glLightfv(GL_LIGHT0, GL_SPECULAR, White);
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glEnable(GL_LIGHT0);
glMaterialfv(GL_FRONT, GL_AMBIENT, Black);
glMaterialf(GL_FRONT, GL_SHININESS, Shininess);
glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, 1);
}
/* Base texture */
glGenTextures(1, &BaseTexture);
glBindTexture(GL_TEXTURE_2D, BaseTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
if (!LoadRGBMipmaps(BASE_TEXTURE_FILE, GL_RGB)) {
printf("Error: couldn't load texture image file %s\n", BASE_TEXTURE_FILE);
exit(1);
}
/* Specular texture */
glGenTextures(1, &SpecularTexture);
glBindTexture(GL_TEXTURE_2D, SpecularTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
if (convolve) {
/* use convolution to blur the texture to simulate a dull finish
* on the object.
*/
GLubyte *img;
GLenum format;
GLint w, h;
GLfloat filter[FILTER_SIZE][FILTER_SIZE][4];
for (h = 0; h < FILTER_SIZE; h++) {
for (w = 0; w < FILTER_SIZE; w++) {
const GLfloat k = 1.0 / (FILTER_SIZE * FILTER_SIZE);
filter[h][w][0] = k;
filter[h][w][1] = k;
filter[h][w][2] = k;
filter[h][w][3] = k;
}
}
glEnable(GL_CONVOLUTION_2D);
glConvolutionParameteri(GL_CONVOLUTION_2D,
GL_CONVOLUTION_BORDER_MODE, GL_CONSTANT_BORDER);
glConvolutionFilter2D(GL_CONVOLUTION_2D, GL_RGBA,
FILTER_SIZE, FILTER_SIZE,
GL_RGBA, GL_FLOAT, filter);
img = LoadRGBImage(SPECULAR_TEXTURE_FILE, &w, &h, &format);
if (!img) {
printf("Error: couldn't load texture image file %s\n",
SPECULAR_TEXTURE_FILE);
exit(1);
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0,
format, GL_UNSIGNED_BYTE, img);
free(img);
}
else {
/* regular path */
if (!LoadRGBMipmaps(SPECULAR_TEXTURE_FILE, GL_RGB)) {
printf("Error: couldn't load texture image file %s\n",
SPECULAR_TEXTURE_FILE);
exit(1);
}
}
/* misc */
glEnable(GL_CULL_FACE);
glEnable(GL_TEXTURE_2D);
glEnable(GL_DEPTH_TEST);
glEnable(GL_NORMALIZE);
glPolygonOffset( -1, -1 );
}
int main( int argc, char *argv[] )
{
glutInitWindowSize(WinWidth, WinHeight);
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow(argv[0] );
glewInit();
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutDisplayFunc( Display );
glutMotionFunc(MouseMotion);
glutMouseFunc(MouseButton);
if (Animate)
glutIdleFunc( Idle );
glutCreateMenu(ModeMenu);
glutAddMenuEntry("Toggle Highlight", DO_SPEC_TEXTURE);
glutAddMenuEntry("Toggle Object", OBJECT);
glutAddMenuEntry("Toggle Animate", ANIMATE);
glutAddMenuEntry("Quit", QUIT);
glutAttachMenu(GLUT_RIGHT_BUTTON);
Init(argc, argv);
glutMainLoop();
return 0;
}
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