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-rw-r--r--progs/demos/cubemap.c138
1 files changed, 117 insertions, 21 deletions
diff --git a/progs/demos/cubemap.c b/progs/demos/cubemap.c
index b3bdd64f68..0df5ff09c3 100644
--- a/progs/demos/cubemap.c
+++ b/progs/demos/cubemap.c
@@ -39,9 +39,13 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <GL/glew.h>
#include "GL/glut.h"
#include "readtex.h"
+#ifndef GL_TEXTURE_CUBE_MAP_SEAMLESS
+#define GL_TEXTURE_CUBE_MAP_SEAMLESS 0x884F
+#endif
static GLfloat Xrot = 0, Yrot = 0;
static GLfloat EyeDist = 10;
@@ -49,8 +53,52 @@ static GLboolean use_vertex_arrays = GL_FALSE;
static GLboolean anim = GL_TRUE;
static GLboolean NoClear = GL_FALSE;
static GLint FrameParity = 0;
+static GLenum FilterIndex = 0;
+static GLint ClampIndex = 0;
+static GLboolean supportFBO = GL_FALSE;
+static GLboolean supportSeamless = GL_FALSE;
+static GLboolean seamless = GL_FALSE;
+
+
+static struct {
+ GLenum mode;
+ const char *name;
+} ClampModes[] = {
+ { GL_CLAMP_TO_EDGE, "GL_CLAMP_TO_EDGE" },
+ { GL_CLAMP_TO_BORDER, "GL_CLAMP_TO_BORDER" },
+ { GL_CLAMP, "GL_CLAMP" },
+ { GL_REPEAT, "GL_REPEAT" }
+};
+
+#define NUM_CLAMP_MODES (sizeof(ClampModes) / sizeof(ClampModes[0]))
+
+
+static struct {
+ GLenum mag_mode, min_mode;
+ const char *name;
+} FilterModes[] = {
+ { GL_NEAREST, GL_NEAREST, "GL_NEAREST, GL_NEAREST" },
+ { GL_NEAREST, GL_LINEAR, "GL_NEAREST, GL_LINEAR" },
+ { GL_NEAREST, GL_NEAREST_MIPMAP_NEAREST, "GL_NEAREST, GL_NEAREST_MIPMAP_NEAREST" },
+ { GL_NEAREST, GL_NEAREST_MIPMAP_LINEAR, "GL_NEAREST, GL_NEAREST_MIPMAP_LINEAR" },
+ { GL_NEAREST, GL_LINEAR_MIPMAP_NEAREST, "GL_NEAREST, GL_LINEAR_MIPMAP_NEAREST" },
+ { GL_NEAREST, GL_LINEAR_MIPMAP_LINEAR, "GL_NEAREST, GL_LINEAR_MIPMAP_LINEAR" },
+
+ { GL_LINEAR, GL_NEAREST, "GL_LINEAR, GL_NEAREST" },
+ { GL_LINEAR, GL_LINEAR, "GL_LINEAR, GL_LINEAR" },
+ { GL_LINEAR, GL_NEAREST_MIPMAP_NEAREST, "GL_LINEAR, GL_NEAREST_MIPMAP_NEAREST" },
+ { GL_LINEAR, GL_NEAREST_MIPMAP_LINEAR, "GL_LINEAR, GL_NEAREST_MIPMAP_LINEAR" },
+ { GL_LINEAR, GL_LINEAR_MIPMAP_NEAREST, "GL_LINEAR, GL_LINEAR_MIPMAP_NEAREST" },
+ { GL_LINEAR, GL_LINEAR_MIPMAP_LINEAR, "GL_LINEAR, GL_LINEAR_MIPMAP_LINEAR" }
+};
+
+#define NUM_FILTER_MODES (sizeof(FilterModes) / sizeof(FilterModes[0]))
-#define eps1 0.99
+
+
+/* The effects of GL_ARB_seamless_cube_map don't show up unless eps1 is 1.0.
+ */
+#define eps1 1.0 /*0.99*/
#define br 20.0 /* box radius */
static const GLfloat tex_coords[] = {
@@ -158,6 +206,8 @@ static void draw_skybox( void )
static void draw( void )
{
+ GLenum wrap;
+
if (NoClear) {
/* This demonstrates how we can avoid calling glClear.
* This method only works if every pixel in the window is painted for
@@ -183,6 +233,23 @@ static void draw( void )
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER,
+ FilterModes[FilterIndex].min_mode);
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER,
+ FilterModes[FilterIndex].mag_mode);
+
+ if (supportSeamless) {
+ if (seamless) {
+ glEnable(GL_TEXTURE_CUBE_MAP_SEAMLESS);
+ } else {
+ glDisable(GL_TEXTURE_CUBE_MAP_SEAMLESS);
+ }
+ }
+ wrap = ClampModes[ClampIndex].mode;
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, wrap);
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, wrap);
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_R, wrap);
+
glPushMatrix(); /*MODELVIEW*/
glTranslatef( 0.0, 0.0, -EyeDist );
@@ -256,10 +323,23 @@ static void key(unsigned char k, int x, int y)
else
glutIdleFunc(NULL);
break;
+ case 'f':
+ FilterIndex = (FilterIndex + 1) % NUM_FILTER_MODES;
+ printf("Tex filter: %s\n", FilterModes[FilterIndex].name);
+ break;
+ case 'c':
+ ClampIndex = (ClampIndex + 1) % NUM_CLAMP_MODES;
+ printf("Tex wrap mode: %s\n", ClampModes[ClampIndex].name);
+ break;
case 'm':
mode = !mode;
set_mode(mode);
break;
+ case 's':
+ seamless = ! seamless;
+ printf("Seamless cube map filtering is %sabled\n",
+ (seamless) ? "en" : "dis" );
+ break;
case 'v':
use_vertex_arrays = ! use_vertex_arrays;
printf( "Vertex arrays are %sabled\n",
@@ -321,7 +401,7 @@ static void reshape(int width, int height)
static void init_checkers( void )
{
#define CUBE_TEX_SIZE 64
- GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][3];
+ GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][4];
static const GLubyte colors[6][3] = {
{ 255, 0, 0 }, /* face 0 - red */
{ 0, 255, 255 }, /* face 1 - cyan */
@@ -343,26 +423,35 @@ static void init_checkers( void )
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+ if (!supportFBO)
+ glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
+
+
/* make colored checkerboard cube faces */
for (f = 0; f < 6; f++) {
for (i = 0; i < CUBE_TEX_SIZE; i++) {
for (j = 0; j < CUBE_TEX_SIZE; j++) {
if ((i/4 + j/4) & 1) {
- image[i][j][0] = colors[f][0];
+ image[i][j][0] = colors[f][2];
image[i][j][1] = colors[f][1];
- image[i][j][2] = colors[f][2];
+ image[i][j][2] = colors[f][0];
+ image[i][j][3] = 255;
}
else {
image[i][j][0] = 255;
image[i][j][1] = 255;
image[i][j][2] = 255;
+ image[i][j][3] = 255;
}
}
}
- glTexImage2D(targets[f], 0, GL_RGB, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
- GL_RGB, GL_UNSIGNED_BYTE, image);
+ glTexImage2D(targets[f], 0, GL_RGBA8, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
+ GL_BGRA, GL_UNSIGNED_BYTE, image);
}
+
+ if (supportFBO)
+ glGenerateMipmapEXT(GL_TEXTURE_CUBE_MAP_ARB);
}
@@ -431,32 +520,36 @@ static void load_envmaps(void)
static void init( GLboolean useImageFiles )
{
- GLenum filter;
+ /* check for extensions */
+ if (!GLEW_ARB_texture_cube_map) {
+ printf("Sorry, this demo requires GL_ARB_texture_cube_map\n");
+ exit(0);
+ }
- /* 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);
- }
+ /* Needed for glGenerateMipmapEXT / auto mipmapping
+ */
+ supportFBO = GLEW_EXT_framebuffer_object;
+
+ if (!supportFBO && !GLEW_SGIS_generate_mipmap) {
+ printf("Sorry, this demo requires GL_EXT_framebuffer_object or "
+ "GL_SGIS_generate_mipmap\n");
+ exit(0);
}
+
+ /* GLEW doesn't know about this extension yet, so use the old GLUT function
+ * to check for availability.
+ */
+ supportSeamless = glutExtensionSupported("GL_ARB_seamless_cube_map");
+
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);
@@ -472,6 +565,8 @@ static void usage(void)
printf("keys:\n");
printf(" SPACE - toggle animation\n");
printf(" CURSOR KEYS - rotation\n");
+ printf(" c - toggle texture clamp/wrap mode\n");
+ printf(" f - toggle texture filter mode\n");
printf(" m - toggle texgen reflection mode\n");
printf(" z/Z - change viewing distance\n");
}
@@ -502,6 +597,7 @@ int main( int argc, char *argv[] )
glutInitWindowSize(600, 500);
glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
glutCreateWindow("Texture Cube Mapping");
+ glewInit();
glutReshapeFunc( reshape );
glutKeyboardFunc( key );
glutSpecialFunc( specialkey );
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-29 12:38:51 +0000