Files
bullet3/Extras/GPUphysics/GPU_physics_demo.cxx

554 lines
16 KiB
C++

#ifndef WIN32
#include <sys/time.h>
#endif
#include <assert.h>
#include <GL/glew.h>
//think different
#if defined(__APPLE__) && !defined (VMDMESA)
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#include <GL/gl.h>
#endif
#include "fboSupport.h"
#include "shaderSupport.h"
enum DebugOptions
{
DRAW_WITHOUT_SHADERS,
DRAW_WITHOUT_PHYSICS,
DRAW_WITHOUT_COLLISIONS,
DRAW_WITHOUT_FORCES,
DRAW_ALL
} ;
DebugOptions debugOpt = DRAW_ALL ;
float frand ( float max )
{
return (float)(rand() % 32767) * max / 32767.0f ;
}
static GLSL_ShaderPair *velocityGenerator ;
static GLSL_ShaderPair *positionGenerator ;
static GLSL_ShaderPair *collisionGenerator ;
static GLSL_ShaderPair *cubeShader ;
static FrameBufferObject *position ;
static FrameBufferObject *rotation ;
static FrameBufferObject *velocity ;
static FrameBufferObject *rotvelocity ;
static FrameBufferObject *force ;
static FrameBufferObject *mass ;
#define TEX_SIZE 128
#define NUM_CUBES ( TEX_SIZE * TEX_SIZE )
#define STRIPS_PER_CUBE 2
#define VERTS_PER_STRIP 8
#define NUM_VERTS ( NUM_CUBES * STRIPS_PER_CUBE * VERTS_PER_STRIP )
static GLuint vbo_vx = 0 ;
static GLuint vbo_tx = 0 ;
static GLuint vbo_co = 0 ;
static float vertices [ NUM_VERTS * 3 ] ;
static float texcoords [ NUM_VERTS * 2 ] ;
static float colours [ NUM_VERTS * 4 ] ;
static int starts [ NUM_CUBES * STRIPS_PER_CUBE ] ;
static int lengths [ NUM_CUBES * STRIPS_PER_CUBE ] ;
static int win_width = 640 ;
static int win_height = 480 ;
void keybd ( unsigned char, int, int )
{
exit ( 0 ) ;
}
void reshape ( int wid, int ht )
{
win_width = wid ;
win_height = ht ;
}
void initGLcontext ( int argc, char **argv, void (*display)(void) )
{
glutInit ( &argc, argv ) ;
glutInitDisplayMode ( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE ) ;
glutInitWindowSize ( win_width, win_height ) ;
glutCreateWindow ( "Shader Math Demo" ) ;
glutDisplayFunc ( display ) ;
glutKeyboardFunc ( keybd ) ;
glutReshapeFunc ( reshape ) ;
glewInit () ;
}
void initMotionTextures ()
{
if ( debugOpt == DRAW_WITHOUT_SHADERS ) return ;
position = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
rotation = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
if ( debugOpt == DRAW_WITHOUT_PHYSICS )
{
velocity = NULL ;
rotvelocity = NULL ;
force = NULL ;
mass = NULL ;
}
else
{
velocity = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
rotvelocity = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
if ( debugOpt == DRAW_WITHOUT_FORCES )
{
force = NULL ;
mass = NULL ;
}
else
{
force = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
mass = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 1, FBO_FLOAT ) ;
}
}
float *positionData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
float *rotationData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
float *velocityData ;
float *rotvelocityData ;
float *forceData ;
float *massData ;
if ( debugOpt == DRAW_WITHOUT_PHYSICS )
{
velocityData = NULL ;
rotvelocityData = NULL ;
forceData = NULL ;
massData = NULL ;
}
else
{
velocityData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
rotvelocityData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
if ( debugOpt == DRAW_WITHOUT_FORCES )
{
forceData = NULL ;
massData = NULL ;
}
else
{
forceData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
massData = new float [ TEX_SIZE * TEX_SIZE ] ;
}
}
/* Give the objects some initial position, rotation, mass, force, etc */
for ( int i = 0 ; i < TEX_SIZE ; i++ )
for ( int j = 0 ; j < TEX_SIZE ; j++ )
{
/*
Start the cubes on a nice, regular 5m grid, 10m above the ground
centered around the origin
*/
positionData [ (i*TEX_SIZE + j) * 3 + 0 ] = 5.0f * (float) (TEX_SIZE/2 - i) ;
positionData [ (i*TEX_SIZE + j) * 3 + 1 ] = 10.0f ;
positionData [ (i*TEX_SIZE + j) * 3 + 2 ] = 5.0f * (float) (TEX_SIZE/2 - j) ;
/* Zero their rotations */
rotationData [ (i*TEX_SIZE + j) * 3 + 0 ] = 0.0f ;
rotationData [ (i*TEX_SIZE + j) * 3 + 1 ] = 0.0f ;
rotationData [ (i*TEX_SIZE + j) * 3 + 2 ] = 0.0f ;
if ( debugOpt != DRAW_WITHOUT_PHYSICS )
{
/* Random (but predominantly upwards) velocities. */
velocityData [ (i*TEX_SIZE + j) * 3 + 0 ] = frand ( 10.0f ) ;
velocityData [ (i*TEX_SIZE + j) * 3 + 1 ] = frand ( 100.0f ) ;
velocityData [ (i*TEX_SIZE + j) * 3 + 2 ] = frand ( 10.0f ) ;
/* Random rotational velocities */
rotvelocityData [ (i*TEX_SIZE + j) * 3 + 0 ] = frand ( 3.0f ) ;
rotvelocityData [ (i*TEX_SIZE + j) * 3 + 1 ] = frand ( 3.0f ) ;
rotvelocityData [ (i*TEX_SIZE + j) * 3 + 2 ] = frand ( 3.0f ) ;
if ( debugOpt != DRAW_WITHOUT_FORCES )
{
/* Zero forces (just gravity) */
forceData [ (i*TEX_SIZE + j) * 3 + 0 ] = 0.0f ;
forceData [ (i*TEX_SIZE + j) * 3 + 1 ] = 0.0f ;
forceData [ (i*TEX_SIZE + j) * 3 + 2 ] = 0.0f ;
/* One kg in weight each */
massData [ i*TEX_SIZE + j ] = 1.0f ;
}
}
}
/* Initialise the textures */
position -> fillTexture ( positionData ) ;
rotation -> fillTexture ( rotationData ) ;
if ( debugOpt != DRAW_WITHOUT_PHYSICS )
{
velocity -> fillTexture ( velocityData ) ;
rotvelocity -> fillTexture ( rotvelocityData ) ;
if ( debugOpt != DRAW_WITHOUT_FORCES )
{
force -> fillTexture ( forceData ) ;
mass -> fillTexture ( massData ) ;
}
}
}
void initPhysicsShaders ()
{
if ( debugOpt == DRAW_WITHOUT_SHADERS ||
debugOpt == DRAW_WITHOUT_PHYSICS )
return ;
if ( debugOpt == DRAW_WITHOUT_FORCES )
{
velocityGenerator = NULL ;
}
else
{
/*
The velocity generator shader calculates:
velocity = old_velocity + delta_T * ( F / m ) ;
*/
velocityGenerator = new GLSL_ShaderPair (
"VelocityGenerator",
NULL, NULL,
"uniform float delta_T ;"
"uniform vec3 g ;"
"uniform sampler2D old_velocity ;"
"uniform sampler2D force ;"
"uniform sampler2D mass ;"
"void main() {"
" gl_FragColor = vec4 ("
" texture2D ( old_velocity, gl_TexCoord[0].st ).xyz +"
" delta_T * ( g +"
" texture2D ( force , gl_TexCoord[0].st ).xyz /"
" texture2D ( mass , gl_TexCoord[0].st ).x),"
" 1.0 ) ; }",
"VelocityGenerator Frag Shader" ) ;
assert ( velocityGenerator -> compiledOK () ) ;
}
/*
The position generater shader calculates:
position = old_position + delta_T * velocity ;
It's also used to update the rotational velocity.
*/
positionGenerator = new GLSL_ShaderPair (
"PositionGenerator",
NULL, NULL,
"uniform float delta_T ;"
"uniform sampler2D old_position ;"
"uniform sampler2D velocity ;"
"void main() {"
" gl_FragColor = vec4 ("
" texture2D ( old_position, gl_TexCoord[0].st ).xyz +"
" texture2D ( velocity , gl_TexCoord[0].st ).xyz *"
" delta_T,"
" 1.0 ) ; }",
"PositionGenerator Frag Shader" ) ;
assert ( positionGenerator -> compiledOK () ) ;
if ( debugOpt == DRAW_WITHOUT_COLLISIONS )
{
collisionGenerator = NULL ;
}
else
{
collisionGenerator = new GLSL_ShaderPair (
"CollisionGenerator",
NULL, NULL,
"uniform sampler2D position ;"
"uniform sampler2D old_velocity ;"
"void main() {"
" vec3 pos = texture2D ( position , gl_TexCoord[0].st ).xyz ;"
" vec3 vel = texture2D ( old_velocity, gl_TexCoord[0].st ).xyz ;"
" if ( pos [ 1 ] < 0.0 ) vel [ 1 ] *= -0.90 ;"
" gl_FragColor = vec4 ( vel, 1.0 ) ; }",
"CollisionGenerator Frag Shader" ) ;
assert ( collisionGenerator -> compiledOK () ) ;
}
}
void initCubeVBO ()
{
float *p = vertices ;
float *t = texcoords ;
float *c = colours ;
for ( int k = 0 ; k < NUM_CUBES * STRIPS_PER_CUBE ; k++ )
{
starts [ k ] = k * VERTS_PER_STRIP ;
lengths [ k ] = VERTS_PER_STRIP ;
}
for ( int i = 0 ; i < TEX_SIZE ; i++ )
for ( int j = 0 ; j < TEX_SIZE ; j++ )
{
int n = i * TEX_SIZE + j ;
/*
I use the colour data to set which cube is which in
the physics textures.
*/
for ( int k = 0 ; k < STRIPS_PER_CUBE * VERTS_PER_STRIP ; k++ )
{
*t++ = ((float)i+0.5f)/(float)TEX_SIZE ;
*t++ = ((float)j+0.5f)/(float)TEX_SIZE ;
*c++ = frand ( 1.0f ) ;
*c++ = frand ( 1.0f ) ;
*c++ = frand ( 1.0f ) ;
*c++ = 1.0f ;
}
float dx, dy, dz ;
if ( debugOpt == DRAW_WITHOUT_SHADERS )
{
dx = 5.0f * (float) (TEX_SIZE/2 - i) ;
dy = 10.0f ;
dz = 5.0f * (float) (TEX_SIZE/2 - j) ;
}
else
{
dx = 0.0f ;
dy = 0.0f ;
dz = 0.0f ;
}
*p++ = -1 + dx ; *p++ = -1 + dy ; *p++ = -1 + dz ;
*p++ = +1 + dx ; *p++ = -1 + dy ; *p++ = -1 + dz ;
*p++ = -1 + dx ; *p++ = +1 + dy ; *p++ = -1 + dz ;
*p++ = +1 + dx ; *p++ = +1 + dy ; *p++ = -1 + dz ;
*p++ = -1 + dx ; *p++ = +1 + dy ; *p++ = +1 + dz ;
*p++ = +1 + dx ; *p++ = +1 + dy ; *p++ = +1 + dz ;
*p++ = -1 + dx ; *p++ = -1 + dy ; *p++ = +1 + dz ;
*p++ = +1 + dx ; *p++ = -1 + dy ; *p++ = +1 + dz ;
*p++ = -1 + dx ; *p++ = +1 + dy ; *p++ = -1 + dz ;
*p++ = -1 + dx ; *p++ = +1 + dy ; *p++ = +1 + dz ;
*p++ = -1 + dx ; *p++ = -1 + dy ; *p++ = -1 + dz ;
*p++ = -1 + dx ; *p++ = -1 + dy ; *p++ = +1 + dz ;
*p++ = +1 + dx ; *p++ = -1 + dy ; *p++ = -1 + dz ;
*p++ = +1 + dx ; *p++ = -1 + dy ; *p++ = +1 + dz ;
*p++ = +1 + dx ; *p++ = +1 + dy ; *p++ = -1 + dz ;
*p++ = +1 + dx ; *p++ = +1 + dy ; *p++ = +1 + dz ;
}
glGenBuffersARB ( 1, & vbo_vx ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_vx ) ;
glBufferDataARB ( GL_ARRAY_BUFFER_ARB, NUM_VERTS * 3 * sizeof(float),
vertices, GL_STATIC_DRAW_ARB ) ;
glGenBuffersARB ( 1, & vbo_tx ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_tx ) ;
glBufferDataARB ( GL_ARRAY_BUFFER_ARB, NUM_VERTS * 2 * sizeof(float),
texcoords, GL_STATIC_DRAW_ARB ) ;
glGenBuffersARB ( 1, & vbo_co ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_co ) ;
glBufferDataARB ( GL_ARRAY_BUFFER_ARB, NUM_VERTS * 4 * sizeof(float),
colours, GL_STATIC_DRAW_ARB ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, 0 ) ;
if ( debugOpt == DRAW_WITHOUT_SHADERS )
cubeShader = NULL ;
else
{
cubeShader = new GLSL_ShaderPair ( "CubeShader", "cubeShader.vert",
"cubeShader.frag" ) ;
assert ( cubeShader -> compiledOK () ) ;
}
}
void drawCubeVBO ()
{
glPushClientAttrib ( GL_CLIENT_VERTEX_ARRAY_BIT ) ;
glEnableClientState ( GL_TEXTURE_COORD_ARRAY ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_tx ) ;
glTexCoordPointer ( 2, GL_FLOAT, 0, vbo_tx ? NULL : texcoords ) ;
glEnableClientState ( GL_COLOR_ARRAY ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_co ) ;
glColorPointer ( 4, GL_FLOAT, 0, vbo_co ? NULL : colours ) ;
glEnableClientState ( GL_VERTEX_ARRAY ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_vx ) ;
glVertexPointer ( 3, GL_FLOAT, 0, vbo_vx ? NULL : vertices ) ;
glMultiDrawArraysEXT ( GL_TRIANGLE_STRIP, (GLint*)starts, (GLint*)lengths,
NUM_CUBES * STRIPS_PER_CUBE ) ;
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, 0 ) ;
glPopClientAttrib () ;
}
void drawCubes ()
{
glMatrixMode ( GL_PROJECTION ) ;
glLoadIdentity () ;
glFrustum ( -1.0f, 1.0f,
-1.0f / ((float)win_width/(float)win_height),
1.0f / ((float)win_width/(float)win_height),
1.0f, 1000000.0f) ;
glMatrixMode ( GL_MODELVIEW ) ;
glLoadIdentity () ;
glTranslatef ( 10.0, -100.0, -500.0 ) ;
glRotatef ( 20.0, 1.0, 0.0, 0.0 ) ;
glEnable ( GL_DEPTH_TEST ) ;
glEnable ( GL_CULL_FACE ) ;
glCullFace ( GL_FRONT ) ;
glClearColor ( 0.7f, 0.7f, 0.7f, 1.0f ) ;
glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ) ;
drawCubeVBO () ;
}
void display ( void )
{
if ( debugOpt != DRAW_WITHOUT_SHADERS &&
debugOpt != DRAW_WITHOUT_PHYSICS )
{
/* Do some simple physics calculations in four stages */
if ( debugOpt != DRAW_WITHOUT_FORCES )
{
velocityGenerator -> use () ;
velocityGenerator -> applyTexture ( "old_velocity", velocity, 0 ) ;
velocityGenerator -> applyTexture ( "force" , force , 1 ) ;
velocityGenerator -> applyTexture ( "mass" , mass , 2 ) ;
velocityGenerator -> setUniform1f ( "delta_T" , 0.016f ) ;
velocityGenerator -> setUniform3f ( "g", 0.0f, -9.8f, 0.0f ) ;
velocity -> paint () ;
}
positionGenerator -> use () ;
positionGenerator -> applyTexture ( "old_position", position, 0 ) ;
positionGenerator -> applyTexture ( "velocity" , velocity, 1 ) ;
positionGenerator -> setUniform1f ( "delta_T", 0.016f ) ;
position -> paint () ;
if ( debugOpt != DRAW_WITHOUT_COLLISIONS )
{
collisionGenerator -> use () ;
collisionGenerator -> applyTexture ( "position" , position, 0 ) ;
collisionGenerator -> applyTexture ( "old_velocity", velocity, 1 ) ;
velocity -> paint () ;
}
positionGenerator -> use () ;
positionGenerator -> applyTexture ( "old_position", rotation , 0 ) ;
positionGenerator -> applyTexture ( "velocity" , rotvelocity, 1 ) ;
positionGenerator -> setUniform1f ( "delta_T", 0.016f ) ;
rotation -> paint () ;
/* Now render the scene using the results */
restoreFrameBuffer () ;
}
glViewport ( 0, 0, win_width, win_height ) ;
if ( debugOpt != DRAW_WITHOUT_SHADERS )
{
cubeShader -> use () ; /* Math = Cube shader */
cubeShader -> applyTexture ( "position", position, 0 ) ;
cubeShader -> applyTexture ( "rotation", rotation, 1 ) ;
}
drawCubes () ;
/* All done! */
glutSwapBuffers () ;
glutPostRedisplay () ;
}
void help ()
{
fprintf ( stderr, "GPUphysics: Usage -\n\n" ) ;
fprintf ( stderr, " GPUphysics_demo [-c][-p][-v][-a]\n\n" ) ;
fprintf ( stderr, "Where:\n" ) ;
fprintf ( stderr, " -s -- Draw with shaders at all\n" ) ;
fprintf ( stderr, " -p -- Draw with shaders but no physics\n" ) ;
fprintf ( stderr, " -c -- Draw with physics but no ground collisions\n" ) ;
fprintf ( stderr, " -f -- Draw with physics but no forces\n" ) ;
fprintf ( stderr, " -a -- Draw with all features enabled [default]\n" ) ;
fprintf ( stderr, "\n" ) ;
}
int main ( int argc, char **argv )
{
debugOpt = DRAW_ALL ;
for ( int i = 1 ; i < argc ; i++ )
{
if ( argv [ i ][ 0 ] == '-' || argv [ i ][ 0 ] == '+' )
for ( int j = 1 ; argv[i][j] != '\0' ; j++ )
switch ( argv [ i ][ j ] )
{
case 's' : debugOpt = DRAW_WITHOUT_SHADERS ; break ;
case 'p' : debugOpt = DRAW_WITHOUT_PHYSICS ; break ;
case 'c' : debugOpt = DRAW_WITHOUT_COLLISIONS ; break ;
case 'f' : debugOpt = DRAW_WITHOUT_FORCES ; break ;
case 'a' : debugOpt = DRAW_ALL ; break ;
default : help () ; exit ( 0 ) ;
}
else
{
help () ;
exit ( 0 ) ;
}
}
initGLcontext ( argc, argv, display ) ;
initMotionTextures () ;
initPhysicsShaders () ;
initCubeVBO () ;
glutMainLoop () ;
return 0 ;
}