progs/objviewer: Wavefront .obj file loader/viewer demo

Adapted from code written by Nate Robins.  See README.txt.

1 files changed, 186 insertions, 0 deletions

diff --git a/progs/objviewer/skybox.c b/progs/objviewer/skybox.c
new file mode 100644
index 00000000000..fb6f0194230
--- /dev/null
+++ b/progs/objviewer/skybox.c
@@ -0,0 +1,186 @@
+
+
+#include <assert.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <GL/glew.h>
+#include <GL/glu.h>
+#include "readtex.h"
+#include "skybox.h"
+
+
+static int
+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);
+      return 0;
+   }
+   assert(format == GL_RGB);
+
+   printf("Load cube face 0x%x: %s %d x %d\n", target, filename, w, h);
+
+   /* <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);
+   return 1;
+}
+
+
+GLuint
+LoadSkyBoxCubeTexture(const char *filePosX,
+                      const char *fileNegX,
+                      const char *filePosY,
+                      const char *fileNegY,
+                      const char *filePosZ,
+                      const char *fileNegZ)
+{
+   GLuint tex;
+
+   glGenTextures(1, &tex);
+   glBindTexture(GL_TEXTURE_CUBE_MAP, tex);
+
+   if (!load(GL_TEXTURE_CUBE_MAP_POSITIVE_X, filePosX, GL_TRUE, GL_TRUE))
+      return 0;
+   if (!load(GL_TEXTURE_CUBE_MAP_NEGATIVE_X, fileNegX, GL_TRUE, GL_TRUE))
+      return 0;
+   if (!load(GL_TEXTURE_CUBE_MAP_POSITIVE_Y, filePosY, 1+GL_FALSE, GL_TRUE))
+      return 0;
+   if (!load(GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, fileNegY, 1+GL_FALSE, GL_TRUE))
+      return 0;
+   if (!load(GL_TEXTURE_CUBE_MAP_POSITIVE_Z, filePosZ, GL_TRUE, GL_TRUE))
+      return 0;
+   if (!load(GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, fileNegZ, GL_TRUE, GL_TRUE))
+      return 0;
+
+   return tex;
+}
+
+
+#define eps1 0.99
+#define br   20.0  /* box radius */
+
+void
+DrawSkyBoxCubeTexture(GLuint tex)
+{
+   struct vertex {
+      float x, y, z, s, t, r;
+   };
+
+   static const struct vertex verts[24] = {
+      /* +X side */
+      { br, -br, -br,  1.0, -eps1, -eps1 },
+      { br, -br,  br,  1.0, -eps1,  eps1 },
+      { br,  br,  br,  1.0,  eps1,  eps1 },
+      { br,  br, -br,  1.0,  eps1, -eps1 },
+
+      /* -X side */
+      { -br,  br, -br,  -1.0,  eps1, -eps1 },
+      { -br,  br,  br,  -1.0,  eps1,  eps1 },
+      { -br, -br,  br,  -1.0, -eps1,  eps1 },
+      { -br, -br, -br,  -1.0, -eps1, -eps1 },
+
+      /* +Y side */
+      {  br,  br, -br,   eps1, 1.0, -eps1 },
+      {  br,  br,  br,   eps1, 1.0,  eps1 },
+      { -br,  br,  br,  -eps1, 1.0,  eps1 },
+      { -br,  br, -br,  -eps1, 1.0, -eps1 },
+
+      /* -Y side */
+      { -br, -br, -br,  -eps1, -1.0, -eps1 },
+      { -br, -br,  br,  -eps1, -1.0,  eps1 },
+      {  br, -br,  br,   eps1, -1.0,  eps1 },
+      {  br, -br, -br,   eps1, -1.0, -eps1 },
+
+      /* +Z side */
+      {  br, -br, br,   eps1, -eps1, 1.0 },
+      { -br, -br, br,  -eps1, -eps1, 1.0 },
+      { -br,  br, br,  -eps1,  eps1, 1.0 },
+      {  br,  br, br,   eps1,  eps1, 1.0 },
+
+      /* -Z side */
+      {  br,  br, -br,   eps1,  eps1, -1.0 },
+      { -br,  br, -br,  -eps1,  eps1, -1.0 },
+      { -br, -br, -br,  -eps1, -eps1, -1.0 },
+      {  br, -br, -br,   eps1, -eps1, -1.0 },
+   };
+
+   static GLuint vbo = 0;
+
+   if (!vbo ) {
+      glGenBuffersARB(1, &vbo);
+      glBindBufferARB(GL_ARRAY_BUFFER_ARB, vbo);
+      glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(verts), verts,
+                      GL_STATIC_DRAW_ARB);
+   }
+   else {
+      glBindBufferARB(GL_ARRAY_BUFFER_ARB, vbo);
+   }
+
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+
+   glVertexPointer(3, GL_FLOAT, sizeof(struct vertex),
+                   (void *) offsetof(struct vertex, x));
+   glTexCoordPointer(3, GL_FLOAT, sizeof(struct vertex),
+                     (void *) offsetof(struct vertex, s));
+   glEnableClientState(GL_VERTEX_ARRAY);
+   glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+
+   glBindTexture(GL_TEXTURE_CUBE_MAP, tex);
+   glEnable(GL_TEXTURE_CUBE_MAP);
+
+   //glDisable(GL_LIGHTING);
+   glDisable(GL_BLEND);
+
+   glDrawArrays(GL_QUADS, 0, 24);
+
+   //glEnable(GL_LIGHTING);
+
+   glDisable(GL_TEXTURE_CUBE_MAP);
+
+   glDisableClientState(GL_VERTEX_ARRAY);
+   glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+}
+