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-rw-r--r--progs/demos/cubemap.c234
1 files changed, 198 insertions, 36 deletions
diff --git a/progs/demos/cubemap.c b/progs/demos/cubemap.c
index 56e7ea1457a..5818337c126 100644
--- a/progs/demos/cubemap.c
+++ b/progs/demos/cubemap.c
@@ -1,4 +1,4 @@
-/* $Id: cubemap.c,v 1.3 2000/06/27 17:04:43 brianp Exp $ */
+/* $Id: cubemap.c,v 1.4 2002/10/25 17:20:26 brianp Exp $ */
/*
* GL_ARB_texture_cube_map demo
@@ -36,25 +36,100 @@
*/
+#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "GL/glut.h"
+#include "../util/readtex.c" /* a hack */
+
static GLfloat Xrot = 0, Yrot = 0;
+static GLfloat EyeDist = 10;
+
+
+static void draw_skybox( void )
+{
+ const GLfloat eps1 = 0.99;
+ const GLfloat br = 20.0; /* box radius */
+
+ glBegin(GL_QUADS);
+
+ /* +X side */
+ glTexCoord3f(1.0, -eps1, -eps1); glVertex3f(br, -br, -br);
+ glTexCoord3f(1.0, -eps1, eps1); glVertex3f(br, -br, br);
+ glTexCoord3f(1.0, eps1, eps1); glVertex3f(br, br, br);
+ glTexCoord3f(1.0, eps1, -eps1); glVertex3f(br, br, -br);
+
+ /* -X side */
+ glTexCoord3f(-1.0, eps1, -eps1); glVertex3f(-br, br, -br);
+ glTexCoord3f(-1.0, eps1, eps1); glVertex3f(-br, br, br);
+ glTexCoord3f(-1.0, -eps1, eps1); glVertex3f(-br, -br, br);
+ glTexCoord3f(-1.0, -eps1, -eps1); glVertex3f(-br, -br, -br);
+
+ /* +Y side */
+ glTexCoord3f(-eps1, 1.0, -eps1); glVertex3f(-br, br, -br);
+ glTexCoord3f(-eps1, 1.0, eps1); glVertex3f(-br, br, br);
+ glTexCoord3f( eps1, 1.0, eps1); glVertex3f( br, br, br);
+ glTexCoord3f( eps1, 1.0, -eps1); glVertex3f( br, br, -br);
+
+ /* -Y side */
+ glTexCoord3f(-eps1, -1.0, -eps1); glVertex3f(-br, -br, -br);
+ glTexCoord3f(-eps1, -1.0, eps1); glVertex3f(-br, -br, br);
+ glTexCoord3f( eps1, -1.0, eps1); glVertex3f( br, -br, br);
+ glTexCoord3f( eps1, -1.0, -eps1); glVertex3f( br, -br, -br);
+
+ /* +Z side */
+ glTexCoord3f( eps1, -eps1, 1.0); glVertex3f( br, -br, br);
+ glTexCoord3f(-eps1, -eps1, 1.0); glVertex3f(-br, -br, br);
+ glTexCoord3f(-eps1, eps1, 1.0); glVertex3f(-br, br, br);
+ glTexCoord3f( eps1, eps1, 1.0); glVertex3f( br, br, br);
+
+ /* -Z side */
+ glTexCoord3f( eps1, eps1, -1.0); glVertex3f( br, br, -br);
+ glTexCoord3f(-eps1, eps1, -1.0); glVertex3f(-br, br, -br);
+ glTexCoord3f(-eps1, -eps1, -1.0); glVertex3f(-br, -br, -br);
+ glTexCoord3f( eps1, -eps1, -1.0); glVertex3f( br, -br, -br);
+
+ glEnd();
+}
static void draw( void )
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
- glMatrixMode(GL_TEXTURE);
- glLoadIdentity();
- glRotatef(Xrot, 1, 0, 0);
- glRotatef(Yrot, 0, 1, 0);
- glutSolidSphere(2.0, 20, 20);
- glMatrixMode(GL_MODELVIEW);
+ glPushMatrix(); /*MODELVIEW*/
+ glTranslatef( 0.0, 0.0, -EyeDist );
+
+ /* skybox */
+ glDisable(GL_TEXTURE_GEN_S);
+ glDisable(GL_TEXTURE_GEN_T);
+ glDisable(GL_TEXTURE_GEN_R);
+
+ glMatrixMode(GL_MODELVIEW);
+ glPushMatrix();
+ glRotatef(Xrot, 1, 0, 0);
+ glRotatef(Yrot, 0, 1, 0);
+ draw_skybox();
+ glPopMatrix();
+
+ /* sphere */
+ glMatrixMode(GL_TEXTURE);
+ glLoadIdentity();
+ glRotatef(-Yrot, 0, 1, 0);
+ glRotatef(-Xrot, 1, 0, 0);
+
+ glEnable(GL_TEXTURE_GEN_S);
+ glEnable(GL_TEXTURE_GEN_T);
+ glEnable(GL_TEXTURE_GEN_R);
+ glutSolidSphere(2.0, 20, 20);
+
+ glLoadIdentity(); /* texture */
+
+ glMatrixMode(GL_MODELVIEW);
+ glPopMatrix();
glutSwapBuffers();
}
@@ -62,7 +137,8 @@ static void draw( void )
static void idle(void)
{
- Yrot += 5.0;
+ GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
+ Yrot = t;
glutPostRedisplay();
}
@@ -81,9 +157,6 @@ static void set_mode(GLuint mode)
glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_NORMAL_MAP_ARB);
printf("GL_NORMAL_MAP_ARB mode\n");
}
- glEnable(GL_TEXTURE_GEN_S);
- glEnable(GL_TEXTURE_GEN_T);
- glEnable(GL_TEXTURE_GEN_R);
}
@@ -105,6 +178,16 @@ static void key(unsigned char k, int x, int y)
mode = !mode;
set_mode(mode);
break;
+ case 'z':
+ EyeDist -= 0.5;
+ if (EyeDist < 6.0)
+ EyeDist = 6.0;
+ break;
+ case 'Z':
+ EyeDist += 0.5;
+ if (EyeDist > 90.0)
+ EyeDist = 90;
+ break;
case 27:
exit(0);
}
@@ -114,15 +197,15 @@ static void key(unsigned char k, int x, int y)
static void specialkey(int key, int x, int y)
{
- GLfloat step = 10;
+ GLfloat step = 5;
(void) x;
(void) y;
switch (key) {
case GLUT_KEY_UP:
- Xrot -= step;
+ Xrot += step;
break;
case GLUT_KEY_DOWN:
- Xrot += step;
+ Xrot -= step;
break;
case GLUT_KEY_LEFT:
Yrot -= step;
@@ -138,17 +221,17 @@ static void specialkey(int key, int x, int y)
/* new window size or exposure */
static void reshape(int width, int height)
{
+ GLfloat ar = (float) width / (float) height;
glViewport(0, 0, (GLint)width, (GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
- glFrustum( -2.0, 2.0, -2.0, 2.0, 6.0, 20.0 );
+ glFrustum( -2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0 );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
- glTranslatef( 0.0, 0.0, -8.0 );
}
-static void init( void )
+static void init_checkers( void )
{
#define CUBE_TEX_SIZE 64
GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][3];
@@ -171,16 +254,6 @@ static void init( void )
GLint i, j, f;
- /* check for extension */
- {
- char *exten = (char *) glGetString(GL_EXTENSIONS);
- if (!strstr(exten, "GL_ARB_texture_cube_map")) {
- printf("Sorry, this demo requires GL_ARB_texture_cube_map\n");
- exit(0);
- }
- }
-
-
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
/* make colored checkerboard cube faces */
@@ -203,18 +276,102 @@ static void init( void )
glTexImage2D(targets[f], 0, GL_RGB, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
GL_RGB, GL_UNSIGNED_BYTE, image);
}
+}
+
-#if 1
- glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
- glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-#else
- glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
- glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-#endif
+static void load(GLenum target, const char *filename,
+ GLboolean flipTB, GLboolean flipLR)
+{
+ GLint w, h;
+ GLenum format;
+ GLubyte *img = LoadRGBImage( filename, &w, &h, &format );
+ if (!img) {
+ printf("Error: couldn't load texture image %s\n", filename);
+ exit(1);
+ }
+ assert(format == GL_RGB);
+
+ /* <sigh> the way the texture cube mapping works, we have to flip
+ * images to make things look right.
+ */
+ if (flipTB) {
+ const int stride = 3 * w;
+ GLubyte temp[3*1024];
+ int i;
+ for (i = 0; i < h / 2; i++) {
+ memcpy(temp, img + i * stride, stride);
+ memcpy(img + i * stride, img + (h - i - 1) * stride, stride);
+ memcpy(img + (h - i - 1) * stride, temp, stride);
+ }
+ }
+ if (flipLR) {
+ const int stride = 3 * w;
+ GLubyte temp[3];
+ GLubyte *row;
+ int i, j;
+ for (i = 0; i < h; i++) {
+ row = img + i * stride;
+ for (j = 0; j < w / 2; j++) {
+ int k = w - j - 1;
+ temp[0] = row[j*3+0];
+ temp[1] = row[j*3+1];
+ temp[2] = row[j*3+2];
+ row[j*3+0] = row[k*3+0];
+ row[j*3+1] = row[k*3+1];
+ row[j*3+2] = row[k*3+2];
+ row[k*3+0] = temp[0];
+ row[k*3+1] = temp[1];
+ row[k*3+2] = temp[2];
+ }
+ }
+ }
+
+ gluBuild2DMipmaps(target, GL_RGB, w, h, format, GL_UNSIGNED_BYTE, img);
+ free(img);
+}
+
+
+static void load_envmaps(void)
+{
+ load(GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB, "right.rgb", GL_TRUE, GL_FALSE);
+ load(GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB, "left.rgb", GL_TRUE, GL_FALSE);
+ load(GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB, "top.rgb", GL_FALSE, GL_TRUE);
+ load(GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB, "bottom.rgb", GL_FALSE, GL_TRUE);
+ load(GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB, "front.rgb", GL_TRUE, GL_FALSE);
+ load(GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB, "back.rgb", GL_TRUE, GL_FALSE);
+}
+
+
+static void init( GLboolean useImageFiles )
+{
+ GLenum filter;
+
+ /* check for extension */
+ {
+ char *exten = (char *) glGetString(GL_EXTENSIONS);
+ if (!strstr(exten, "GL_ARB_texture_cube_map")) {
+ printf("Sorry, this demo requires GL_ARB_texture_cube_map\n");
+ exit(0);
+ }
+ }
+ printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER));
+
+ if (useImageFiles) {
+ load_envmaps();
+ filter = GL_LINEAR;
+ }
+ else {
+ init_checkers();
+ filter = GL_NEAREST;
+ }
+
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, filter);
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, filter);
glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glEnable(GL_TEXTURE_CUBE_MAP_ARB);
+ glEnable(GL_DEPTH_TEST);
glClearColor(.3, .3, .3, 0);
glColor3f( 1.0, 1.0, 1.0 );
@@ -229,16 +386,21 @@ static void usage(void)
printf(" SPACE - toggle animation\n");
printf(" CURSOR KEYS - rotation\n");
printf(" m - toggle texgen reflection mode\n");
+ printf(" z/Z - change viewing distance\n");
}
int main( int argc, char *argv[] )
{
glutInitWindowPosition(0, 0);
- glutInitWindowSize(300, 300);
+ glutInitWindowSize(600, 500);
glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
glutCreateWindow("Texture Cube Maping");
- init();
+
+ if (argc > 1 && strcmp(argv[1] , "-i") == 0)
+ init( 1 );
+ else
+ init( 0 );
glutReshapeFunc( reshape );
glutKeyboardFunc( key );
glutSpecialFunc( specialkey );
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