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xenocara/dist/Mesa/progs/tests/projtex.c

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/* projtex.c - by David Yu and David Blythe, SGI */
/**
** Demonstrates simple projective texture mapping.
**
** Button1 changes view, Button2 moves texture.
**
** (See: Segal, Korobkin, van Widenfelt, Foran, and Haeberli
** "Fast Shadows and Lighting Effects Using Texture Mapping", SIGGRAPH '92)
**
** 1994,1995 -- David G Yu
**
** cc -o projtex projtex.c texture.c -lglut -lGLU -lGL -lX11 -lm
**/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#if 0
#include "texture.h"
#else
#include "../util/readtex.c"
#endif
/* Some <math.h> files do not define M_PI... */
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
#define MAX_TEX 4
int NumTextures = 1;
int winWidth, winHeight;
GLboolean redrawContinuously = GL_FALSE;
float angle, axis[3];
enum MoveModes {
MoveNone, MoveView, MoveObject, MoveTexture
};
enum MoveModes mode = MoveNone;
GLfloat objectXform[4][4];
GLfloat textureXform[MAX_TEX][4][4];
void (*drawObject) (void);
void (*loadTexture) (void);
GLboolean textureEnabled = GL_TRUE;
GLboolean showProjection = GL_TRUE;
GLboolean linearFilter = GL_TRUE;
char *texFilename[MAX_TEX] = {
"../images/girl.rgb",
"../images/tile.rgb",
"../images/bw.rgb",
"../images/reflect.rgb"
};
GLfloat zoomFactor = 1.0;
/*****************************************************************/
void ActiveTexture(int i)
{
glActiveTextureARB(i);
}
/* matrix = identity */
void
matrixIdentity(GLfloat matrix[16])
{
matrix[0] = 1.0;
matrix[1] = 0.0;
matrix[2] = 0.0;
matrix[3] = 0.0;
matrix[4] = 0.0;
matrix[5] = 1.0;
matrix[6] = 0.0;
matrix[7] = 0.0;
matrix[8] = 0.0;
matrix[9] = 0.0;
matrix[10] = 1.0;
matrix[11] = 0.0;
matrix[12] = 0.0;
matrix[13] = 0.0;
matrix[14] = 0.0;
matrix[15] = 1.0;
}
/* matrix2 = transpose(matrix1) */
void
matrixTranspose(GLfloat matrix2[16], GLfloat matrix1[16])
{
matrix2[0] = matrix1[0];
matrix2[1] = matrix1[4];
matrix2[2] = matrix1[8];
matrix2[3] = matrix1[12];
matrix2[4] = matrix1[1];
matrix2[5] = matrix1[5];
matrix2[6] = matrix1[9];
matrix2[7] = matrix1[13];
matrix2[8] = matrix1[2];
matrix2[9] = matrix1[6];
matrix2[10] = matrix1[10];
matrix2[11] = matrix1[14];
matrix2[12] = matrix1[3];
matrix2[13] = matrix1[7];
matrix2[14] = matrix1[14];
matrix2[15] = matrix1[15];
}
/*****************************************************************/
/* load SGI .rgb image (pad with a border of the specified width and color) */
#if 0
static void
imgLoad(char *filenameIn, int borderIn, GLfloat borderColorIn[4],
int *wOut, int *hOut, GLubyte ** imgOut)
{
int border = borderIn;
int width, height;
int w, h;
GLubyte *image, *img, *p;
int i, j, components;
image = (GLubyte *) read_texture(filenameIn, &width, &height, &components);
w = width + 2 * border;
h = height + 2 * border;
img = (GLubyte *) calloc(w * h, 4 * sizeof(unsigned char));
p = img;
for (j = -border; j < height + border; ++j) {
for (i = -border; i < width + border; ++i) {
if (0 <= j && j <= height - 1 && 0 <= i && i <= width - 1) {
p[0] = image[4 * (j * width + i) + 0];
p[1] = image[4 * (j * width + i) + 1];
p[2] = image[4 * (j * width + i) + 2];
p[3] = 0xff;
} else {
p[0] = borderColorIn[0] * 0xff;
p[1] = borderColorIn[1] * 0xff;
p[2] = borderColorIn[2] * 0xff;
p[3] = borderColorIn[3] * 0xff;
}
p += 4;
}
}
free(image);
*wOut = w;
*hOut = h;
*imgOut = img;
}
#endif
/*****************************************************************/
/* Load the image file specified on the command line as the current texture */
void
loadImageTextures(void)
{
GLfloat borderColor[4] =
{1.0, 1.0, 1.0, 1.0};
int tex;
for (tex = 0; tex < NumTextures; tex++) {
GLubyte *image, *texData3, *texData4;
GLint imgWidth, imgHeight;
GLenum imgFormat;
int i, j;
printf("loading %s\n", texFilename[tex]);
image = LoadRGBImage(texFilename[tex], &imgWidth, &imgHeight, &imgFormat);
if (!image) {
printf("can't find %s\n", texFilename[tex]);
exit(1);
}
assert(imgFormat == GL_RGB);
/* scale to 256x256 */
texData3 = malloc(256 * 256 * 4);
texData4 = malloc(256 * 256 * 4);
assert(texData3);
assert(texData4);
gluScaleImage(imgFormat, imgWidth, imgHeight, GL_UNSIGNED_BYTE, image,
256, 256, GL_UNSIGNED_BYTE, texData3);
/* convert to rgba */
for (i = 0; i < 256 * 256; i++) {
texData4[i*4+0] = texData3[i*3+0];
texData4[i*4+1] = texData3[i*3+1];
texData4[i*4+2] = texData3[i*3+2];
texData4[i*4+3] = 128;
}
/* put transparent border around image */
for (i = 0; i < 256; i++) {
texData4[i*4+0] = 255;
texData4[i*4+1] = 255;
texData4[i*4+2] = 255;
texData4[i*4+3] = 0;
}
j = 256 * 255 * 4;
for (i = 0; i < 256; i++) {
texData4[j + i*4+0] = 255;
texData4[j + i*4+1] = 255;
texData4[j + i*4+2] = 255;
texData4[j + i*4+3] = 0;
}
for (i = 0; i < 256; i++) {
j = i * 256 * 4;
texData4[j+0] = 255;
texData4[j+1] = 255;
texData4[j+2] = 255;
texData4[j+3] = 0;
}
for (i = 0; i < 256; i++) {
j = i * 256 * 4 + 255 * 4;
texData4[j+0] = 255;
texData4[j+1] = 255;
texData4[j+2] = 255;
texData4[j+3] = 0;
}
ActiveTexture(GL_TEXTURE0_ARB + tex);
glBindTexture(GL_TEXTURE_2D, tex + 1);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 256, 256, 0,
GL_RGBA, GL_UNSIGNED_BYTE, texData4);
if (linearFilter) {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
} else {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor);
}
}
/* Create a simple spotlight pattern and make it the current texture */
void
loadSpotlightTexture(void)
{
static int texWidth = 64, texHeight = 64;
static GLubyte *texData;
GLfloat borderColor[4] =
{0.1, 0.1, 0.1, 1.0};
if (!texData) {
GLubyte *p;
int i, j;
texData = (GLubyte *) malloc(texWidth * texHeight * 4 * sizeof(GLubyte));
p = texData;
for (j = 0; j < texHeight; ++j) {
float dy = (texHeight * 0.5 - j + 0.5) / (texHeight * 0.5);
for (i = 0; i < texWidth; ++i) {
float dx = (texWidth * 0.5 - i + 0.5) / (texWidth * 0.5);
float r = cos(M_PI / 2.0 * sqrt(dx * dx + dy * dy));
float c;
r = (r < 0) ? 0 : r * r;
c = 0xff * (r + borderColor[0]);
p[0] = (c <= 0xff) ? c : 0xff;
c = 0xff * (r + borderColor[1]);
p[1] = (c <= 0xff) ? c : 0xff;
c = 0xff * (r + borderColor[2]);
p[2] = (c <= 0xff) ? c : 0xff;
c = 0xff * (r + borderColor[3]);
p[3] = (c <= 0xff) ? c : 0xff;
p += 4;
}
}
}
if (linearFilter) {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
} else {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor);
gluBuild2DMipmaps(GL_TEXTURE_2D, 4, texWidth, texHeight,
GL_RGBA, GL_UNSIGNED_BYTE, texData);
}
/*****************************************************************/
void
checkErrors(void)
{
GLenum error;
while ((error = glGetError()) != GL_NO_ERROR) {
fprintf(stderr, "Error: %s\n", (char *) gluErrorString(error));
}
}
void
drawCube(void)
{
glBegin(GL_QUADS);
glNormal3f(-1.0, 0.0, 0.0);
glColor3f(0.80, 0.50, 0.50);
glVertex3f(-0.5, -0.5, -0.5);
glVertex3f(-0.5, -0.5, 0.5);
glVertex3f(-0.5, 0.5, 0.5);
glVertex3f(-0.5, 0.5, -0.5);
glNormal3f(1.0, 0.0, 0.0);
glColor3f(0.50, 0.80, 0.50);
glVertex3f(0.5, 0.5, 0.5);
glVertex3f(0.5, -0.5, 0.5);
glVertex3f(0.5, -0.5, -0.5);
glVertex3f(0.5, 0.5, -0.5);
glNormal3f(0.0, -1.0, 0.0);
glColor3f(0.50, 0.50, 0.80);
glVertex3f(-0.5, -0.5, -0.5);
glVertex3f(0.5, -0.5, -0.5);
glVertex3f(0.5, -0.5, 0.5);
glVertex3f(-0.5, -0.5, 0.5);
glNormal3f(0.0, 1.0, 0.0);
glColor3f(0.50, 0.80, 0.80);
glVertex3f(0.5, 0.5, 0.5);
glVertex3f(0.5, 0.5, -0.5);
glVertex3f(-0.5, 0.5, -0.5);
glVertex3f(-0.5, 0.5, 0.5);
glNormal3f(0.0, 0.0, -1.0);
glColor3f(0.80, 0.50, 0.80);
glVertex3f(-0.5, -0.5, -0.5);
glVertex3f(-0.5, 0.5, -0.5);
glVertex3f(0.5, 0.5, -0.5);
glVertex3f(0.5, -0.5, -0.5);
glNormal3f(0.0, 0.0, 1.0);
glColor3f(1.00, 0.80, 0.50);
glVertex3f(0.5, 0.5, 0.5);
glVertex3f(-0.5, 0.5, 0.5);
glVertex3f(-0.5, -0.5, 0.5);
glVertex3f(0.5, -0.5, 0.5);
glEnd();
}
void
drawDodecahedron(void)
{
#define A (0.5 * 1.61803) /* (sqrt(5) + 1) / 2 */
#define B (0.5 * 0.61803) /* (sqrt(5) - 1) / 2 */
#define C (0.5 * 1.0)
GLfloat vertexes[20][3] =
{
{-A, 0.0, B},
{-A, 0.0, -B},
{A, 0.0, -B},
{A, 0.0, B},
{B, -A, 0.0},
{-B, -A, 0.0},
{-B, A, 0.0},
{B, A, 0.0},
{0.0, B, -A},
{0.0, -B, -A},
{0.0, -B, A},
{0.0, B, A},
{-C, -C, C},
{-C, -C, -C},
{C, -C, -C},
{C, -C, C},
{-C, C, C},
{-C, C, -C},
{C, C, -C},
{C, C, C},
};
#undef A
#undef B
#undef C
GLint polygons[12][5] =
{
{0, 12, 10, 11, 16},
{1, 17, 8, 9, 13},
{2, 14, 9, 8, 18},
{3, 19, 11, 10, 15},
{4, 14, 2, 3, 15},
{5, 12, 0, 1, 13},
{6, 17, 1, 0, 16},
{7, 19, 3, 2, 18},
{8, 17, 6, 7, 18},
{9, 14, 4, 5, 13},
{10, 12, 5, 4, 15},
{11, 19, 7, 6, 16},
};
int i;
glColor3f(0.75, 0.75, 0.75);
for (i = 0; i < 12; ++i) {
GLfloat *p0, *p1, *p2, d;
GLfloat u[3], v[3], n[3];
p0 = &vertexes[polygons[i][0]][0];
p1 = &vertexes[polygons[i][1]][0];
p2 = &vertexes[polygons[i][2]][0];
u[0] = p2[0] - p1[0];
u[1] = p2[1] - p1[1];
u[2] = p2[2] - p1[2];
v[0] = p0[0] - p1[0];
v[1] = p0[1] - p1[1];
v[2] = p0[2] - p1[2];
n[0] = u[1] * v[2] - u[2] * v[1];
n[1] = u[2] * v[0] - u[0] * v[2];
n[2] = u[0] * v[1] - u[1] * v[0];
d = 1.0 / sqrt(n[0] * n[0] + n[1] * n[1] + n[2] * n[2]);
n[0] *= d;
n[1] *= d;
n[2] *= d;
glBegin(GL_POLYGON);
glNormal3fv(n);
glVertex3fv(p0);
glVertex3fv(p1);
glVertex3fv(p2);
glVertex3fv(vertexes[polygons[i][3]]);
glVertex3fv(vertexes[polygons[i][4]]);
glEnd();
}
}
void
drawSphere(void)
{
int numMajor = 24;
int numMinor = 32;
float radius = 0.8;
double majorStep = (M_PI / numMajor);
double minorStep = (2.0 * M_PI / numMinor);
int i, j;
glColor3f(0.50, 0.50, 0.50);
for (i = 0; i < numMajor; ++i) {
double a = i * majorStep;
double b = a + majorStep;
double r0 = radius * sin(a);
double r1 = radius * sin(b);
GLfloat z0 = radius * cos(a);
GLfloat z1 = radius * cos(b);
glBegin(GL_TRIANGLE_STRIP);
for (j = 0; j <= numMinor; ++j) {
double c = j * minorStep;
GLfloat x = cos(c);
GLfloat y = sin(c);
glNormal3f((x * r0) / radius, (y * r0) / radius, z0 / radius);
glTexCoord2f(j / (GLfloat) numMinor, i / (GLfloat) numMajor);
glVertex3f(x * r0, y * r0, z0);
glNormal3f((x * r1) / radius, (y * r1) / radius, z1 / radius);
glTexCoord2f(j / (GLfloat) numMinor, (i + 1) / (GLfloat) numMajor);
glVertex3f(x * r1, y * r1, z1);
}
glEnd();
}
}
/*****************************************************************/
float xmin = -0.035, xmax = 0.035;
float ymin = -0.035, ymax = 0.035;
float nnear = 0.1;
float ffar = 1.9;
float distance = -1.0;
static void
loadTextureProjection(int texUnit, GLfloat m[16])
{
GLfloat mInverse[4][4];
/* Should use true inverse, but since m consists only of rotations, we can
just use the transpose. */
matrixTranspose((GLfloat *) mInverse, m);
ActiveTexture(GL_TEXTURE0_ARB + texUnit);
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glTranslatef(0.5, 0.5, 0.0);
glScalef(0.5, 0.5, 1.0);
glFrustum(xmin, xmax, ymin, ymax, nnear, ffar);
glTranslatef(0.0, 0.0, distance);
glMultMatrixf((GLfloat *) mInverse);
glMatrixMode(GL_MODELVIEW);
}
static void
drawTextureProjection(void)
{
float t = ffar / nnear;
GLfloat n[4][3];
GLfloat f[4][3];
n[0][0] = xmin;
n[0][1] = ymin;
n[0][2] = -(nnear + distance);
n[1][0] = xmax;
n[1][1] = ymin;
n[1][2] = -(nnear + distance);
n[2][0] = xmax;
n[2][1] = ymax;
n[2][2] = -(nnear + distance);
n[3][0] = xmin;
n[3][1] = ymax;
n[3][2] = -(nnear + distance);
f[0][0] = xmin * t;
f[0][1] = ymin * t;
f[0][2] = -(ffar + distance);
f[1][0] = xmax * t;
f[1][1] = ymin * t;
f[1][2] = -(ffar + distance);
f[2][0] = xmax * t;
f[2][1] = ymax * t;
f[2][2] = -(ffar + distance);
f[3][0] = xmin * t;
f[3][1] = ymax * t;
f[3][2] = -(ffar + distance);
glColor3f(1.0, 1.0, 0.0);
glBegin(GL_LINE_LOOP);
glVertex3fv(n[0]);
glVertex3fv(n[1]);
glVertex3fv(n[2]);
glVertex3fv(n[3]);
glVertex3fv(f[3]);
glVertex3fv(f[2]);
glVertex3fv(f[1]);
glVertex3fv(f[0]);
glVertex3fv(n[0]);
glVertex3fv(n[1]);
glVertex3fv(f[1]);
glVertex3fv(f[0]);
glVertex3fv(f[3]);
glVertex3fv(f[2]);
glVertex3fv(n[2]);
glVertex3fv(n[3]);
glEnd();
}
/*****************************************************************/
void
initialize(void)
{
GLfloat light0Pos[4] =
{0.3, 0.3, 0.0, 1.0};
GLfloat matAmb[4] =
{0.01, 0.01, 0.01, 1.00};
GLfloat matDiff[4] =
{0.65, 0.65, 0.65, 1.00};
GLfloat matSpec[4] =
{0.30, 0.30, 0.30, 1.00};
GLfloat matShine = 10.0;
GLfloat eyePlaneS[] =
{1.0, 0.0, 0.0, 0.0};
GLfloat eyePlaneT[] =
{0.0, 1.0, 0.0, 0.0};
GLfloat eyePlaneR[] =
{0.0, 0.0, 1.0, 0.0};
GLfloat eyePlaneQ[] =
{0.0, 0.0, 0.0, 1.0};
int i;
/* Setup Misc. */
glClearColor(0.41, 0.41, 0.31, 0.0);
glEnable(GL_DEPTH_TEST);
/* glLineWidth(2.0);*/
glCullFace(GL_FRONT);
glEnable(GL_CULL_FACE);
glMatrixMode(GL_PROJECTION);
glFrustum(-0.5, 0.5, -0.5, 0.5, 1, 3);
glMatrixMode(GL_MODELVIEW);
glTranslatef(0, 0, -2);
matrixIdentity((GLfloat *) objectXform);
for (i = 0; i < NumTextures; i++) {
matrixIdentity((GLfloat *) textureXform[i]);
}
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0, 1, 0, 1, -1, 1);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glRasterPos2i(0, 0);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
/* Setup Lighting */
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, matAmb);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, matDiff);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, matSpec);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, matShine);
glEnable(GL_COLOR_MATERIAL);
glLightfv(GL_LIGHT0, GL_POSITION, light0Pos);
glEnable(GL_LIGHT0);
glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
glEnable(GL_LIGHTING);
/* Setup Texture */
(*loadTexture) ();
for (i = 0; i < NumTextures; i++) {
ActiveTexture(GL_TEXTURE0_ARB + i);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_S, GL_EYE_PLANE, eyePlaneS);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_T, GL_EYE_PLANE, eyePlaneT);
glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_R, GL_EYE_PLANE, eyePlaneR);
glTexGeni(GL_Q, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGenfv(GL_Q, GL_EYE_PLANE, eyePlaneQ);
}
}
void
display(void)
{
int i;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
if (textureEnabled) {
if (mode == MoveTexture || mode == MoveView) {
/* Have OpenGL compute the new transformation (simple but slow). */
for (i = 0; i < NumTextures; i++) {
glPushMatrix();
glLoadIdentity();
#if 0
if (i & 1)
glRotatef(angle, axis[0], axis[1], axis[2]);
else
#endif
glRotatef(angle*(i+1), axis[0], axis[1], axis[2]);
glMultMatrixf((GLfloat *) textureXform[i]);
glGetFloatv(GL_MODELVIEW_MATRIX, (GLfloat *) textureXform[i]);
glPopMatrix();
}
}
for (i = 0; i < NumTextures; i++) {
loadTextureProjection(i, (GLfloat *) textureXform[i]);
}
if (showProjection) {
for (i = 0; i < NumTextures; i++) {
ActiveTexture(GL_TEXTURE0_ARB + i);
glPushMatrix();
glMultMatrixf((GLfloat *) textureXform[i]);
glDisable(GL_LIGHTING);
drawTextureProjection();
glEnable(GL_LIGHTING);
glPopMatrix();
}
}
for (i = 0; i < NumTextures; i++) {
ActiveTexture(GL_TEXTURE0_ARB + i);
glEnable(GL_TEXTURE_2D);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
glEnable(GL_TEXTURE_GEN_R);
glEnable(GL_TEXTURE_GEN_Q);
}
}
if (mode == MoveObject || mode == MoveView) {
/* Have OpenGL compute the new transformation (simple but slow). */
glPushMatrix();
glLoadIdentity();
glRotatef(angle, axis[0], axis[1], axis[2]);
glMultMatrixf((GLfloat *) objectXform);
glGetFloatv(GL_MODELVIEW_MATRIX, (GLfloat *) objectXform);
glPopMatrix();
}
glPushMatrix();
glMultMatrixf((GLfloat *) objectXform);
(*drawObject) ();
glPopMatrix();
for (i = 0; i < NumTextures; i++) {
ActiveTexture(GL_TEXTURE0_ARB + i);
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glDisable(GL_TEXTURE_GEN_R);
glDisable(GL_TEXTURE_GEN_Q);
}
if (zoomFactor > 1.0) {
glDisable(GL_DEPTH_TEST);
glCopyPixels(0, 0, winWidth / zoomFactor, winHeight / zoomFactor, GL_COLOR);
glEnable(GL_DEPTH_TEST);
}
glFlush();
glutSwapBuffers();
checkErrors();
}
/*****************************************************************/
/* simple trackball-like motion control */
float lastPos[3];
int lastTime;
void
ptov(int x, int y, int width, int height, float v[3])
{
float d, a;
/* project x,y onto a hemi-sphere centered within width, height */
v[0] = (2.0 * x - width) / width;
v[1] = (height - 2.0 * y) / height;
d = sqrt(v[0] * v[0] + v[1] * v[1]);
v[2] = cos((M_PI / 2.0) * ((d < 1.0) ? d : 1.0));
a = 1.0 / sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
v[0] *= a;
v[1] *= a;
v[2] *= a;
}
void
startMotion(int x, int y, int but, int time)
{
if (but == GLUT_LEFT_BUTTON) {
mode = MoveView;
} else if (but == GLUT_MIDDLE_BUTTON) {
mode = MoveTexture;
} else {
return;
}
lastTime = time;
ptov(x, y, winWidth, winHeight, lastPos);
}
void
animate(void)
{
glutPostRedisplay();
}
void
vis(int visible)
{
if (visible == GLUT_VISIBLE) {
if (redrawContinuously)
glutIdleFunc(animate);
} else {
if (redrawContinuously)
glutIdleFunc(NULL);
}
}
void
stopMotion(int but, int time)
{
if ((but == GLUT_LEFT_BUTTON && mode == MoveView) ||
(but == GLUT_MIDDLE_BUTTON && mode == MoveTexture)) {
} else {
return;
}
if (time == lastTime) {
/* redrawContinuously = GL_TRUE;*/
glutIdleFunc(animate);
} else {
angle = 0.0;
redrawContinuously = GL_FALSE;
glutIdleFunc(0);
}
if (!redrawContinuously) {
mode = MoveNone;
}
}
void
trackMotion(int x, int y)
{
float curPos[3], dx, dy, dz;
ptov(x, y, winWidth, winHeight, curPos);
dx = curPos[0] - lastPos[0];
dy = curPos[1] - lastPos[1];
dz = curPos[2] - lastPos[2];
angle = 90.0 * sqrt(dx * dx + dy * dy + dz * dz);
axis[0] = lastPos[1] * curPos[2] - lastPos[2] * curPos[1];
axis[1] = lastPos[2] * curPos[0] - lastPos[0] * curPos[2];
axis[2] = lastPos[0] * curPos[1] - lastPos[1] * curPos[0];
lastTime = glutGet(GLUT_ELAPSED_TIME);
lastPos[0] = curPos[0];
lastPos[1] = curPos[1];
lastPos[2] = curPos[2];
glutPostRedisplay();
}
/*****************************************************************/
void
object(void)
{
static int object;
object++;
object %= 3;
switch (object) {
case 0:
drawObject = drawCube;
break;
case 1:
drawObject = drawDodecahedron;
break;
case 2:
drawObject = drawSphere;
break;
default:
break;
}
}
static void
nop(void)
{
}
void
texture(void)
{
static int texture = 0;
texture++;
texture %= 3;
if (texture == 1 && texFilename == NULL) {
/* Skip file texture if not loaded. */
texture++;
}
switch (texture) {
case 0:
loadTexture = nop;
textureEnabled = GL_FALSE;
break;
case 1:
loadTexture = loadImageTextures;
(*loadTexture) ();
textureEnabled = GL_TRUE;
break;
case 2:
loadTexture = loadSpotlightTexture;
(*loadTexture) ();
textureEnabled = GL_TRUE;
break;
default:
break;
}
}
void
help(void)
{
printf("'h' - help\n");
printf("'l' - toggle linear/nearest filter\n");
printf("'s' - toggle projection frustum\n");
printf("'t' - toggle projected texture\n");
printf("'o' - toggle object\n");
printf("'z' - increase zoom factor\n");
printf("'Z' - decrease zoom factor\n");
printf("left mouse - move view\n");
printf("middle mouse - move projection\n");
}
/* ARGSUSED1 */
void
key(unsigned char key, int x, int y)
{
switch (key) {
case '\033':
exit(0);
break;
case 'l':
linearFilter = !linearFilter;
(*loadTexture) ();
break;
case 's':
showProjection = !showProjection;
break;
case 't':
texture();
break;
case 'o':
object();
break;
case 'z':
zoomFactor += 1.0;
glPixelZoom(zoomFactor, zoomFactor);
glViewport(0, 0, winWidth / zoomFactor, winHeight / zoomFactor);
break;
case 'Z':
zoomFactor -= 1.0;
if (zoomFactor < 1.0)
zoomFactor = 1.0;
glPixelZoom(zoomFactor, zoomFactor);
glViewport(0, 0, winWidth / zoomFactor, winHeight / zoomFactor);
break;
case 'h':
help();
break;
}
glutPostRedisplay();
}
void
mouse(int button, int state, int x, int y)
{
if (state == GLUT_DOWN)
startMotion(x, y, button, glutGet(GLUT_ELAPSED_TIME));
else if (state == GLUT_UP)
stopMotion(button, glutGet(GLUT_ELAPSED_TIME));
glutPostRedisplay();
}
void
reshape(int w, int h)
{
winWidth = w;
winHeight = h;
glViewport(0, 0, w / zoomFactor, h / zoomFactor);
}
void
menu(int selection)
{
if (selection == 666) {
exit(0);
}
key((unsigned char) selection, 0, 0);
}
int
main(int argc, char **argv)
{
glutInit(&argc, argv);
if (argc > 1) {
NumTextures = atoi(argv[1]);
}
assert(NumTextures <= MAX_TEX);
glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
(void) glutCreateWindow("projtex");
loadTexture = loadImageTextures;
drawObject = drawCube;
initialize();
glutDisplayFunc(display);
glutKeyboardFunc(key);
glutReshapeFunc(reshape);
glutMouseFunc(mouse);
glutMotionFunc(trackMotion);
glutVisibilityFunc(vis);
glutCreateMenu(menu);
glutAddMenuEntry("Toggle showing projection", 's');
glutAddMenuEntry("Switch texture", 't');
glutAddMenuEntry("Switch object", 'o');
glutAddMenuEntry("Toggle filtering", 'l');
glutAddMenuEntry("Quit", 666);
glutAttachMenu(GLUT_RIGHT_BUTTON);
texture();
glutMainLoop();
return 0; /* ANSI C requires main to return int. */
}
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