Add new demo "fbo_firecube".

Tests fbo render-to-texture for various internal texture image formats.

2 files changed, 1042 insertions, 0 deletions

diff --git a/progs/demos/Makefile b/progs/demos/Makefile
index 7fde77f0b4..fedce1cc3d 100644
--- a/progs/demos/Makefile
+++ b/progs/demos/Makefile
@@ -27,6 +27,7 @@ PROGS = \
 	cubemap \
 	drawpix \
 	engine \
+	fbo_firecube \
 	fire \
 	fogcoord \
 	fplight \
diff --git a/progs/demos/fbo_firecube.c b/progs/demos/fbo_firecube.c
new file mode 100644
index 0000000000..0f01476d3f
--- /dev/null
+++ b/progs/demos/fbo_firecube.c
@@ -0,0 +1,1041 @@
+/*
+ * Draw the "fire" test program on the six faces of a cube using
+ * fbo render-to-texture.
+ * 
+ * Much of the code comes from David Bucciarelli's "fire" 
+ * test program. The rest basically from Brian Paul's "gearbox" and
+ * fbotexture programs.
+ *
+ * By pressing the 'q' key, you can make the driver choose different
+ * internal texture RGBA formats by giving it different "format" and "type"
+ * arguments to the glTexImage2D function that creates the texture
+ * image being rendered to. If the driver doesn't support a texture image
+ * format as a render target, it will usually fall back to software when
+ * drawing the "fire" image, and frame-rate should drop considerably.
+ *
+ * Performance: 
+ * The rendering speed of this program is usually dictated by fill rate
+ * and the fact that software fallbacks for glBitMap makes the driver
+ * operate synchronously. Low-end UMA hardware will probably see around
+ * 35 fps with the help screen disabled and 32bpp window- and user
+ * frame-buffers (2008).
+ *
+ * This program is released under GPL, following the "fire" licensing.
+ *
+ * Authors:
+ *   David Bucciarelli ("fire")
+ *   Brian Paul ("gearbox", "fbotexture")
+ *   Thomas Hellstrom (Putting it together)
+ *
+ */
+
+#define GL_GLEXT_PROTOTYPES
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <GL/glut.h>
+#include "readtex.h"
+
+
+/*
+ * Format of texture we render to.
+ */
+
+#define TEXINTFORMAT GL_RGBA
+
+static GLuint texTypes[] = 
+   {GL_UNSIGNED_BYTE,
+    GL_UNSIGNED_INT_8_8_8_8_REV,
+    GL_UNSIGNED_SHORT_1_5_5_5_REV,
+    GL_UNSIGNED_SHORT_4_4_4_4_REV,
+    GL_UNSIGNED_INT_8_8_8_8,
+    GL_UNSIGNED_SHORT_5_5_5_1,
+    GL_UNSIGNED_SHORT_4_4_4_4,
+    GL_UNSIGNED_INT_8_8_8_8_REV,
+    GL_UNSIGNED_SHORT_1_5_5_5_REV,
+    GL_UNSIGNED_SHORT_4_4_4_4_REV,
+    GL_UNSIGNED_INT_8_8_8_8,
+    GL_UNSIGNED_SHORT_5_5_5_1,
+    GL_UNSIGNED_SHORT_4_4_4_4,
+    GL_UNSIGNED_SHORT_5_6_5,
+    GL_UNSIGNED_SHORT_5_6_5_REV,
+    GL_UNSIGNED_SHORT_5_6_5,
+    GL_UNSIGNED_SHORT_5_6_5_REV};
+
+static GLuint texFormats[] = 
+   {GL_RGBA,
+    GL_RGBA,
+    GL_RGBA,
+    GL_RGBA,
+    GL_RGBA,
+    GL_RGBA,
+    GL_RGBA,
+    GL_BGRA,
+    GL_BGRA,
+    GL_BGRA,
+    GL_BGRA,
+    GL_BGRA,
+    GL_BGRA,
+    GL_RGB,
+    GL_RGB,
+    GL_BGR,
+    GL_BGR};
+
+static const char *texNames[] = 
+   {"GL_RGBA GL_UNSIGNED_BYTE",
+    "GL_RGBA GL_UNSIGNED_INT_8_8_8_8_REV",
+    "GL_RGBA GL_UNSIGNED_SHORT_1_5_5_5_REV",
+    "GL_RGBA GL_UNSIGNED_SHORT_4_4_4_4_REV",
+    "GL_RGBA GL_UNSIGNED_INT_8_8_8_8",
+    "GL_RGBA GL_UNSIGNED_INT_5_5_5_1",
+    "GL_RGBA GL_UNSIGNED_INT_4_4_4_4",
+    "GL_BGRA GL_UNSIGNED_INT_8_8_8_8_REV",
+    "GL_BGRA GL_UNSIGNED_SHORT_1_5_5_5_REV",
+    "GL_BGRA GL_UNSIGNED_SHORT_4_4_4_4_REV",
+    "GL_BGRA GL_UNSIGNED_INT_8_8_8_8",
+    "GL_BGRA GL_UNSIGNED_INT_5_5_5_1",
+    "GL_BGRA GL_UNSIGNED_INT_4_4_4_4",
+    "GL_RGB GL_UNSIGNED_INT_5_6_5",
+    "GL_RGB GL_UNSIGNED_INT_5_6_5_REV",
+    "GL_BGR GL_UNSIGNED_INT_5_6_5",
+    "BL_BGR GL_UNSIGNED_INT_5_6_5_REV"};
+
+
+
+
+#ifndef M_PI
+#define M_PI 3.1415926535
+#endif
+
+#define vinit(a,i,j,k) {			\
+      (a)[0]=i;					\
+      (a)[1]=j;					\
+      (a)[2]=k;					\
+   }
+
+#define vinit4(a,i,j,k,w) {			\
+      (a)[0]=i;					\
+      (a)[1]=j;					\
+      (a)[2]=k;					\
+      (a)[3]=w;					\
+   }
+
+
+#define vadds(a,dt,b) {				\
+      (a)[0]+=(dt)*(b)[0];			\
+      (a)[1]+=(dt)*(b)[1];			\
+      (a)[2]+=(dt)*(b)[2];			\
+   }
+
+#define vequ(a,b) {				\
+      (a)[0]=(b)[0];				\
+      (a)[1]=(b)[1];				\
+      (a)[2]=(b)[2];				\
+   }
+
+#define vinter(a,dt,b,c) {			\
+      (a)[0]=(dt)*(b)[0]+(1.0-dt)*(c)[0];	\
+      (a)[1]=(dt)*(b)[1]+(1.0-dt)*(c)[1];	\
+      (a)[2]=(dt)*(b)[2]+(1.0-dt)*(c)[2];	\
+   }
+
+#define clamp(a)        ((a) < 0.0 ? 0.0 : ((a) < 1.0 ? (a) : 1.0))
+
+#define vclamp(v) {				\
+      (v)[0]=clamp((v)[0]);			\
+      (v)[1]=clamp((v)[1]);			\
+      (v)[2]=clamp((v)[2]);			\
+   }
+
+static GLint WinWidth = 800, WinHeight = 800;
+static GLint TexWidth, TexHeight;
+static GLuint TexObj;
+static GLuint MyFB;
+static GLuint DepthRB;
+static GLboolean WireFrame = GL_FALSE;
+static GLint texType = 0;
+
+static GLint T0 = 0;
+static GLint Frames = 0;
+static GLint Win = 0;
+
+static GLfloat ViewRotX = 20.0, ViewRotY = 30.0, ViewRotZ = 0.0;
+static GLfloat CubeRot = 0.0;
+
+static void
+CheckError(int line)
+{
+   GLenum err = glGetError();
+   if (err) {
+      printf("GL Error 0x%x at line %d\n", (int) err, line);
+      exit(1);
+   }
+}
+
+
+static void
+cleanup(void)
+{
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+   glDeleteFramebuffersEXT(1, &MyFB);
+   glDeleteRenderbuffersEXT(1, &DepthRB);
+   glDeleteTextures(1, &TexObj);
+   glutDestroyWindow(Win);
+}
+
+static GLint NiceFog = 1;
+
+#define DIMP 20.0
+#define DIMTP 16.0
+
+#define RIDCOL 0.4
+
+#define NUMTREE 50
+#define TREEINR 2.5
+#define TREEOUTR 8.0
+
+#define AGRAV -9.8
+
+typedef struct
+{
+   int age;
+   float p[3][3];
+   float v[3];
+   float c[3][4];
+}
+   part;
+
+static float treepos[NUMTREE][3];
+
+static float black[3] = { 0.0, 0.0, 0.0 };
+static float blu[3] = { 1.0, 0.2, 0.0 };
+static float blu2[3] = { 1.0, 1.0, 0.0 };
+
+static float fogcolor[4] = { 1.0, 1.0, 1.0, 1.0 };
+
+static float q[4][3] = {
+   {-DIMP, 0.0, -DIMP},
+   {DIMP, 0.0, -DIMP},
+   {DIMP, 0.0, DIMP},
+   {-DIMP, 0.0, DIMP}
+};
+
+static float qt[4][2] = {
+   {-DIMTP, -DIMTP},
+   {DIMTP, -DIMTP},
+   {DIMTP, DIMTP},
+   {-DIMTP, DIMTP}
+};
+
+static int np;
+static float eject_r, dt, maxage, eject_vy, eject_vl;
+static short shadows;
+static float ridtri;
+static int fog = 0;
+static int help = 1;
+
+static part *p;
+
+static GLuint groundid;
+static GLuint treeid;
+
+static float obs[3] = { 2.0, 1.0, 0.0 };
+static float dir[3];
+static float v = 0.0;
+static float alpha = -84.0;
+static float beta = 90.0;
+
+static float
+vrnd(void)
+{
+   return (((float) rand()) / RAND_MAX);
+}
+
+static void
+setnewpart(part * p)
+{
+   float a, v[3], *c;
+
+   p->age = 0;
+
+   a = vrnd() * 3.14159265359 * 2.0;
+
+   vinit(v, sin(a) * eject_r * vrnd(), 0.15, cos(a) * eject_r * vrnd());
+   vinit(p->p[0], v[0] + vrnd() * ridtri, v[1] + vrnd() * ridtri,
+	 v[2] + vrnd() * ridtri);
+   vinit(p->p[1], v[0] + vrnd() * ridtri, v[1] + vrnd() * ridtri,
+	 v[2] + vrnd() * ridtri);
+   vinit(p->p[2], v[0] + vrnd() * ridtri, v[1] + vrnd() * ridtri,
+	 v[2] + vrnd() * ridtri);
+
+   vinit(p->v, v[0] * eject_vl / (eject_r / 2),
+	 vrnd() * eject_vy + eject_vy / 2, v[2] * eject_vl / (eject_r / 2));
+
+   c = blu;
+
+   vinit4(p->c[0], c[0] * ((1.0 - RIDCOL) + vrnd() * RIDCOL),
+	  c[1] * ((1.0 - RIDCOL) + vrnd() * RIDCOL),
+	  c[2] * ((1.0 - RIDCOL) + vrnd() * RIDCOL), 1.0);
+   vinit4(p->c[1], c[0] * ((1.0 - RIDCOL) + vrnd() * RIDCOL),
+	  c[1] * ((1.0 - RIDCOL) + vrnd() * RIDCOL),
+	  c[2] * ((1.0 - RIDCOL) + vrnd() * RIDCOL), 1.0);
+   vinit4(p->c[2], c[0] * ((1.0 - RIDCOL) + vrnd() * RIDCOL),
+	  c[1] * ((1.0 - RIDCOL) + vrnd() * RIDCOL),
+	  c[2] * ((1.0 - RIDCOL) + vrnd() * RIDCOL), 1.0);
+}
+
+static void
+setpart(part * p)
+{
+   float fact;
+
+   if (p->p[0][1] < 0.1) {
+      setnewpart(p);
+      return;
+   }
+
+   p->v[1] += AGRAV * dt;
+
+   vadds(p->p[0], dt, p->v);
+   vadds(p->p[1], dt, p->v);
+   vadds(p->p[2], dt, p->v);
+
+   p->age++;
+
+   if ((p->age) > maxage) {
+      vequ(p->c[0], blu2);
+      vequ(p->c[1], blu2);
+      vequ(p->c[2], blu2);
+   }
+   else {
+      fact = 1.0 / maxage;
+      vadds(p->c[0], fact, blu2);
+      vclamp(p->c[0]);
+      p->c[0][3] = fact * (maxage - p->age);
+
+      vadds(p->c[1], fact, blu2);
+      vclamp(p->c[1]);
+      p->c[1][3] = fact * (maxage - p->age);
+
+      vadds(p->c[2], fact, blu2);
+      vclamp(p->c[2]);
+      p->c[2][3] = fact * (maxage - p->age);
+   }
+}
+
+static void
+drawtree(float x, float y, float z)
+{
+   glBegin(GL_QUADS);
+   glTexCoord2f(0.0, 0.0);
+   glVertex3f(x - 1.5, y + 0.0, z);
+
+   glTexCoord2f(1.0, 0.0);
+   glVertex3f(x + 1.5, y + 0.0, z);
+
+   glTexCoord2f(1.0, 1.0);
+   glVertex3f(x + 1.5, y + 3.0, z);
+
+   glTexCoord2f(0.0, 1.0);
+   glVertex3f(x - 1.5, y + 3.0, z);
+
+
+   glTexCoord2f(0.0, 0.0);
+   glVertex3f(x, y + 0.0, z - 1.5);
+
+   glTexCoord2f(1.0, 0.0);
+   glVertex3f(x, y + 0.0, z + 1.5);
+
+   glTexCoord2f(1.0, 1.0);
+   glVertex3f(x, y + 3.0, z + 1.5);
+
+   glTexCoord2f(0.0, 1.0);
+   glVertex3f(x, y + 3.0, z - 1.5);
+
+   glEnd();
+
+}
+
+static void
+calcposobs(void)
+{
+   dir[0] = sin(alpha * M_PI / 180.0);
+   dir[2] = cos(alpha * M_PI / 180.0) * sin(beta * M_PI / 180.0);
+   dir[1] = cos(beta * M_PI / 180.0);
+
+   if (dir[0] < 1.0e-5 && dir[0] > -1.0e-5)
+      dir[0] = 0;
+   if (dir[1] < 1.0e-5 && dir[1] > -1.0e-5)
+      dir[1] = 0;
+   if (dir[2] < 1.0e-5 && dir[2] > -1.0e-5)
+      dir[2] = 0;
+
+   obs[0] += v * dir[0];
+   obs[1] += v * dir[1];
+   obs[2] += v * dir[2];
+}
+
+static void
+printstring(void *font, const char *string)
+{
+   int len, i;
+
+   len = (int) strlen(string);
+   for (i = 0; i < len; i++)
+      glutBitmapCharacter(font, string[i]);
+}
+
+
+static void
+printhelp(void)
+{
+   glColor4f(0.0, 0.0, 0.0, 0.5);
+   glRecti(40, 40, 600, 440);
+
+   glColor3f(1.0, 0.0, 0.0);
+   glRasterPos2i(300, 420);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Help");
+
+   glRasterPos2i(60, 390);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "h - Toggle Help");
+
+   glRasterPos2i(60, 360);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "t - Increase particle size");
+   glRasterPos2i(60, 330);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "T - Decrease particle size");
+
+   glRasterPos2i(60, 300);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "r - Increase emission radius");
+   glRasterPos2i(60, 270);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "R - Decrease emission radius");
+
+   glRasterPos2i(60, 240);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "f - Toggle Fog");
+   glRasterPos2i(60, 210);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "s - Toggle shadows");
+   glRasterPos2i(60, 180);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "q - Toggle texture format & type");
+   glRasterPos2i(60, 150);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "a - Increase velocity");
+   glRasterPos2i(60, 120);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "z - Decrease velocity");
+   glRasterPos2i(60, 90);
+   printstring(GLUT_BITMAP_TIMES_ROMAN_24,  "Arrow Keys - Rotate");
+}
+
+
+static void
+drawfire(void)
+{
+   static char frbuf[80] = "";
+   int j;
+   static double t0 = -1.;
+   double t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
+   if (t0 < 0.0)
+      t0 = t;
+   dt = (t - t0) * 1.0;
+   t0 = t;
+
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+
+   glDisable(GL_LIGHTING);
+
+   glShadeModel(GL_FLAT);
+
+   glEnable(GL_BLEND);
+   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+   glEnable(GL_FOG);
+   glFogi(GL_FOG_MODE, GL_EXP);
+   glFogfv(GL_FOG_COLOR, fogcolor);
+   glFogf(GL_FOG_DENSITY, 0.1);
+
+
+   glViewport(0, 0, (GLint) TexWidth, (GLint) TexHeight);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   gluPerspective(70.0, TexWidth/ (float) TexHeight, 0.1, 30.0);
+
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+
+   if (NiceFog)
+      glHint(GL_FOG_HINT, GL_NICEST);
+   else
+      glHint(GL_FOG_HINT, GL_DONT_CARE);
+
+   glEnable(GL_DEPTH_TEST);
+
+   if (fog)
+      glEnable(GL_FOG);
+   else
+      glDisable(GL_FOG);
+
+   glDepthMask(GL_TRUE);
+   glClearColor(1.0, 1.0, 1.0, 1.0);
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+
+   glPushMatrix();
+   calcposobs();
+   gluLookAt(obs[0], obs[1], obs[2],
+	     obs[0] + dir[0], obs[1] + dir[1], obs[2] + dir[2],
+	     0.0, 1.0, 0.0);
+
+   glColor4f(1.0, 1.0, 1.0, 1.0);
+
+   glEnable(GL_TEXTURE_2D);
+
+   glBindTexture(GL_TEXTURE_2D, groundid);
+   glBegin(GL_QUADS);
+   glTexCoord2fv(qt[0]);
+   glVertex3fv(q[0]);
+   glTexCoord2fv(qt[1]);
+   glVertex3fv(q[1]);
+   glTexCoord2fv(qt[2]);
+   glVertex3fv(q[2]);
+   glTexCoord2fv(qt[3]);
+   glVertex3fv(q[3]);
+   glEnd();
+
+   glEnable(GL_ALPHA_TEST);
+   glAlphaFunc(GL_GEQUAL, 0.9);
+
+   glBindTexture(GL_TEXTURE_2D, treeid);
+   for (j = 0; j < NUMTREE; j++)
+      drawtree(treepos[j][0], treepos[j][1], treepos[j][2]);
+
+   glDisable(GL_TEXTURE_2D);
+   glDepthMask(GL_FALSE);
+   glDisable(GL_ALPHA_TEST);
+
+   if (shadows) {
+      glBegin(GL_TRIANGLES);
+      for (j = 0; j < np; j++) {
+	 glColor4f(black[0], black[1], black[2], p[j].c[0][3]);
+	 glVertex3f(p[j].p[0][0], 0.1, p[j].p[0][2]);
+
+	 glColor4f(black[0], black[1], black[2], p[j].c[1][3]);
+	 glVertex3f(p[j].p[1][0], 0.1, p[j].p[1][2]);
+
+	 glColor4f(black[0], black[1], black[2], p[j].c[2][3]);
+	 glVertex3f(p[j].p[2][0], 0.1, p[j].p[2][2]);
+      }
+      glEnd();
+   }
+
+   glBegin(GL_TRIANGLES);
+   for (j = 0; j < np; j++) {
+      glColor4fv(p[j].c[0]);
+      glVertex3fv(p[j].p[0]);
+
+      glColor4fv(p[j].c[1]);
+      glVertex3fv(p[j].p[1]);
+
+      glColor4fv(p[j].c[2]);
+      glVertex3fv(p[j].p[2]);
+
+      setpart(&p[j]);
+   }
+   glEnd();
+
+
+   glDisable(GL_TEXTURE_2D);
+   glDisable(GL_ALPHA_TEST);
+   glDisable(GL_DEPTH_TEST);
+   glDisable(GL_FOG);
+
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glOrtho(-0.5, 639.5, -0.5, 479.5
+	   , -1.0, 1.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+
+   glColor3f(1.0, 0.0, 0.0);
+   glRasterPos2i(10, 10);
+   printstring(GLUT_BITMAP_HELVETICA_18, frbuf);
+   glColor3f(0.0, 0.0, 1.0);
+   glRasterPos2i(10, 450);
+   printstring(GLUT_BITMAP_HELVETICA_18, texNames[texType]);
+   glColor3f(1.0, 0.0, 0.0);
+   glRasterPos2i(10, 470);
+   printstring(GLUT_BITMAP_HELVETICA_10,
+	       "Fire V1.5 Written by David Bucciarelli (tech.hmw@plus.it)");
+
+   if (help)
+      printhelp();
+
+   glPopMatrix();
+   glDepthMask(GL_TRUE);
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);   
+   Frames++;
+
+   {
+      GLint t = glutGet(GLUT_ELAPSED_TIME);
+      if (t - T0 >= 2000) {
+	 GLfloat seconds = (t - T0) / 1000.0;
+	 GLfloat fps = Frames / seconds;
+	 sprintf(frbuf, "Frame rate: %f", fps);
+	 T0 = t;
+	 Frames = 0;
+      }
+   }
+   
+}
+
+static void
+regen_texImage(void)
+{
+   glBindTexture(GL_TEXTURE_2D, TexObj);
+   glTexImage2D(GL_TEXTURE_2D, 0, TEXINTFORMAT, TexWidth, TexHeight, 0,
+		texFormats[texType], texTypes[texType], NULL);
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+			     GL_TEXTURE_2D, TexObj, 0);
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+}
+
+static void
+key(unsigned char key, int x, int y)
+{
+   switch (key) {
+   case 27:
+      cleanup();
+      exit(0);
+      break;
+
+   case 'a':
+      v += 0.0005;
+      break;
+   case 'z':
+      v -= 0.0005;
+      break;
+   case 'h':
+      help = (!help);
+      break;
+   case 'f':
+      fog = (!fog);
+      break;
+   case 's':
+      shadows = !shadows;
+      break;
+   case 'R':
+      eject_r -= 0.03;
+      break;
+   case 'r':
+      eject_r += 0.03;
+      break;
+   case 't':
+      ridtri += 0.005;
+      break;
+   case 'T':
+      ridtri -= 0.005;
+      break;
+   case 'v':
+      ViewRotZ += 5.0;
+      break;
+   case 'V':
+      ViewRotZ -= 5.0;
+      break;
+   case 'w':
+      WireFrame = !WireFrame;
+      break;
+   case 'q':
+      if (++texType > 16)
+	 texType = 0;
+      regen_texImage();
+      break;
+   case 'n':
+      NiceFog = !NiceFog;
+      printf("NiceFog %d\n", NiceFog);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+static void
+inittextures(void)
+{
+   GLenum gluerr;
+   GLubyte tex[128][128][4];
+
+   glGenTextures(1, &groundid);
+   glBindTexture(GL_TEXTURE_2D, groundid);
+
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
+   if (!LoadRGBMipmaps("../images/s128.rgb", GL_RGB)) {
+      fprintf(stderr, "Error reading a texture.\n");
+      exit(-1);
+   }
+
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+		   GL_LINEAR_MIPMAP_LINEAR);
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
+
+   glGenTextures(1, &treeid);
+   glBindTexture(GL_TEXTURE_2D, treeid);
+
+   if (1)
+      {
+	 int w, h;
+	 GLenum format;
+	 int x, y;
+	 GLubyte *image = LoadRGBImage("../images/tree3.rgb", &w, &h, &format);
+
+	 if (!image) {
+	    fprintf(stderr, "Error reading a texture.\n");
+	    exit(-1);
+	 }
+
+	 for (y = 0; y < 128; y++)
+	    for (x = 0; x < 128; x++) {
+	       tex[x][y][0] = image[(y + x * 128) * 3];
+	       tex[x][y][1] = image[(y + x * 128) * 3 + 1];
+	       tex[x][y][2] = image[(y + x * 128) * 3 + 2];
+	       if ((tex[x][y][0] == tex[x][y][1]) &&
+		   (tex[x][y][1] == tex[x][y][2]) && (tex[x][y][2] == 255))
+		  tex[x][y][3] = 0;
+	       else
+		  tex[x][y][3] = 255;
+	    }
+
+	 if ((gluerr = gluBuild2DMipmaps(GL_TEXTURE_2D, 4, 128, 128, GL_RGBA,
+					 GL_UNSIGNED_BYTE, (GLvoid *) (tex)))) {
+	    fprintf(stderr, "GLULib%s\n", (char *) gluErrorString(gluerr));
+	    exit(-1);
+	 }
+      }
+   else {
+      if (!LoadRGBMipmaps("../images/tree2.rgba", GL_RGBA)) {
+	 fprintf(stderr, "Error reading a texture.\n");
+	 exit(-1);
+      }
+   }
+
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+		   GL_LINEAR_MIPMAP_LINEAR);
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+}
+
+static void
+inittree(void)
+{
+   int i;
+   float dist;
+
+   for (i = 0; i < NUMTREE; i++)
+      do {
+	 treepos[i][0] = vrnd() * TREEOUTR * 2.0 - TREEOUTR;
+	 treepos[i][1] = 0.0;
+	 treepos[i][2] = vrnd() * TREEOUTR * 2.0 - TREEOUTR;
+	 dist =
+	    sqrt(treepos[i][0] * treepos[i][0] +
+		 treepos[i][2] * treepos[i][2]);
+      } while ((dist < TREEINR) || (dist > TREEOUTR));
+}
+
+static int 
+init_fire(int ac, char *av[])
+{
+   int i;
+
+   np = 800;
+   eject_r = -0.65;
+   dt = 0.015;
+   eject_vy = 4;
+   eject_vl = 1;
+   shadows = 1;
+   ridtri = 0.25;
+
+   maxage = 1.0 / dt;
+
+   if (ac == 2)
+      np = atoi(av[1]);
+
+
+   inittextures();
+
+   p = (part *) malloc(sizeof(part) * np);
+
+   for (i = 0; i < np; i++)
+      setnewpart(&p[i]);
+
+   inittree();
+
+   return (0);
+}
+
+
+
+
+
+
+static void
+DrawCube(void)
+{
+   static const GLfloat texcoords[4][2] = {
+      { 0, 0 }, { 1, 0 }, { 1, 1 }, { 0, 1 }
+   };
+   static const GLfloat vertices[4][2] = {
+      { -1, -1 }, { 1, -1 }, { 1, 1 }, { -1, 1 }
+   };
+   static const GLfloat xforms[6][4] = {
+      {   0, 0, 1, 0 },
+      {  90, 0, 1, 0 },
+      { 180, 0, 1, 0 },
+      { 270, 0, 1, 0 },
+      {  90, 1, 0, 0 },
+      { -90, 1, 0, 0 }
+   };
+   static const GLfloat mat[4] = { 1.0, 1.0, 0.5, 1.0 };
+   GLint i, j;
+
+   glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, mat);
+   glEnable(GL_TEXTURE_2D);
+
+   glPushMatrix();
+   glRotatef(ViewRotX, 1.0, 0.0, 0.0);
+   glRotatef(15, 1, 0, 0);
+   glRotatef(CubeRot, 0, 1, 0);
+   glScalef(4, 4, 4);
+
+   for (i = 0; i < 6; i++) {
+      glPushMatrix();
+      glRotatef(xforms[i][0], xforms[i][1], xforms[i][2], xforms[i][3]);
+      glTranslatef(0, 0, 1.1);
+      glBegin(GL_POLYGON);
+      glNormal3f(0, 0, 1);
+      for (j = 0; j < 4; j++) {
+	 glTexCoord2fv(texcoords[j]);
+	 glVertex2fv(vertices[j]);
+      }
+      glEnd();
+      glPopMatrix();
+   }
+   glPopMatrix();
+
+   glDisable(GL_TEXTURE_2D);
+}
+
+
+static void
+draw(void)
+{
+   float ar;
+   static GLfloat pos[4] = {5.0, 5.0, 10.0, 0.0};
+
+   drawfire();
+
+   glLightfv(GL_LIGHT0, GL_POSITION, pos);
+   glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL,
+		 GL_SEPARATE_SPECULAR_COLOR);
+
+   glEnable(GL_LIGHTING);
+   glEnable(GL_LIGHT0);
+   glEnable(GL_DEPTH_TEST);
+   glEnable(GL_NORMALIZE);
+   glDisable(GL_BLEND);
+   glDisable(GL_FOG);
+
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef(0.0, 0.0, -40.0);
+
+   glClear(GL_DEPTH_BUFFER_BIT);
+
+   /* draw textured cube */
+
+   glViewport(0, 0, WinWidth, WinHeight);
+   glClearColor(0.5, 0.5, 0.8, 0.0);
+   glClear(GL_COLOR_BUFFER_BIT);
+
+   ar = (float) (WinWidth) / WinHeight;
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-ar, ar, -1.0, 1.0, 5.0, 60.0);
+   glMatrixMode(GL_MODELVIEW);
+   glBindTexture(GL_TEXTURE_2D, TexObj);
+
+   DrawCube();
+
+   /* finish up */
+   glutSwapBuffers();
+}
+
+
+static void
+idle(void)
+{
+   static double t0 = -1.;
+   double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
+   if (t0 < 0.0)
+      t0 = t;
+   dt = t - t0;
+   t0 = t;
+
+   CubeRot = fmod(CubeRot + 15.0 * dt, 360.0);  /* 15 deg/sec */
+
+   glutPostRedisplay();
+}
+
+
+/* change view angle */
+static void
+special(int k, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (k) {
+   case GLUT_KEY_UP:
+      ViewRotX += 5.0;
+      break;
+   case GLUT_KEY_DOWN:
+      ViewRotX -= 5.0;
+      break;
+   case GLUT_KEY_LEFT:
+      ViewRotY += 5.0;
+      break;
+   case GLUT_KEY_RIGHT:
+      ViewRotY -= 5.0;
+      break;
+   default:
+      return;
+   }
+   glutPostRedisplay();
+}
+
+
+/* new window size or exposure */
+static void
+reshape(int width, int height)
+{
+   WinWidth = width;
+   WinHeight = height;
+}
+
+
+static void 
+init_fbotexture()
+{
+   GLint i;
+
+   /* gen framebuffer id, delete it, do some assertions, just for testing */
+   glGenFramebuffersEXT(1, &MyFB);
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+   glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &i);
+
+   /* Make texture object/image */
+   glGenTextures(1, &TexObj);
+   glBindTexture(GL_TEXTURE_2D, TexObj);
+   /* make one image level. */
+   glTexImage2D(GL_TEXTURE_2D, 0, TEXINTFORMAT, TexWidth, TexHeight, 0,
+		texFormats[texType], texTypes[texType], NULL);
+
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
+
+   CheckError(__LINE__);
+
+   /* Render color to texture */
+   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+			     GL_TEXTURE_2D, TexObj, 0);
+   CheckError(__LINE__);
+
+
+   /* make depth renderbuffer */
+   glGenRenderbuffersEXT(1, &DepthRB);
+   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRB);
+   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT16,
+			    TexWidth, TexHeight);
+   CheckError(__LINE__);
+   glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
+				   GL_RENDERBUFFER_DEPTH_SIZE_EXT, &i);
+   CheckError(__LINE__);
+   printf("Depth renderbuffer size = %d bits\n", i);
+
+   /* attach DepthRB to MyFB */
+   glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
+				GL_RENDERBUFFER_EXT, DepthRB);
+   CheckError(__LINE__);
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+   /*
+    * Check for completeness.
+    */
+
+}
+
+
+static void
+init(int argc, char *argv[])
+{
+   GLint i;
+
+   if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
+      fprintf(stderr, "Sorry, GL_EXT_framebuffer_object is required!\n");
+      exit(1);
+   }
+
+   TexWidth = 512;
+   TexHeight = 512;
+
+   init_fbotexture();
+   init_fire(argc, argv);
+
+
+   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));
+      }
+   }
+}
+
+
+static void 
+visible(int vis)
+{
+   if (vis == GLUT_VISIBLE)
+      glutIdleFunc(idle);
+   else
+      glutIdleFunc(NULL);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+
+   glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+
+   glutInitWindowSize(WinWidth, WinHeight);
+   Win = glutCreateWindow("fbo_firecube");
+   init(argc, argv);
+
+   glutDisplayFunc(draw);
+   glutReshapeFunc(reshape);
+   glutKeyboardFunc(key);
+   glutSpecialFunc(special);
+   glutVisibilityFunc(visible);
+
+   glutMainLoop();
+   return 0;             /* ANSI C requires main to return int. */
+}