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Added simple collision detection.

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This commit is contained in:
sjbaker
2006-10-01 03:45:08 +00:00
parent 2aaab1ab1a
commit 9ebc440ee5
5 changed files with 329 additions and 153 deletions
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439
Extras/GPUphysics/GPU_physics_demo.cpp
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@@ -11,15 +11,11 @@ enum DebugOptions
DRAW_ALL
} ;
inline float idToFloat ( int i, int j )
{
return float ( (i*2) & 255 ) + float ( (j*2) & 255 ) / 256.0f ;
}
static float *positionData = NULL ;
static float *rotationData = NULL ;
static bool noVertexTextureSupport = false ;
static float *collisionData = NULL ;
static bool noVertexTextureSupport = false ;
static DebugOptions debugOpt = DRAW_ALL ;
void checkVertexTextureSupport ( bool disableVertexTextureSupport )
@@ -62,6 +58,12 @@ void checkVertexTextureSupport ( bool disableVertexTextureSupport )
}
int irand ( int max )
{
return rand() % max ;
}
float frand ( float max )
{
return (float)(rand() % 32767) * max / 32767.0f ;
@@ -71,7 +73,8 @@ float frand ( float max )
static GLSL_ShaderPair *velocityGenerator ;
static GLSL_ShaderPair *positionGenerator ;
static GLSL_ShaderPair *grndCollisionGenerator ;
static GLSL_ShaderPair *forceGenerator ;
static GLSL_ShaderPair *collisionGenerator ;
static GLSL_ShaderPair *forceGenerator ;
static GLSL_ShaderPair *cubeShader ;
static FrameBufferObject *position ;
@@ -79,16 +82,20 @@ static FrameBufferObject *rotation ;
static FrameBufferObject *velocity ;
static FrameBufferObject *rotvelocity ;
static FrameBufferObject *force ;
static FrameBufferObject *new_force ;
static FrameBufferObject *massSizeX ;
static FrameBufferObject *old ;
static FrameBufferObject *collisions ;
#define TEX_SIZE 128
#define TEX_SIZE 16
#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 )
GLuint queries [ NUM_CUBES ] ;
static GLuint vbo_vx = 0 ;
static GLuint vbo_tx = 0 ;
static GLuint vbo_co = 0 ;
@@ -101,6 +108,28 @@ static int lengths [ NUM_CUBES * STRIPS_PER_CUBE ] ;
static int win_width = 640 ;
static int win_height = 480 ;
inline int idToIndex ( int x, int y )
{
/*
Convert a coordinate pair within the texture to an integer
1D array index (eg to index into the data array for that texture)
by multiplying the Y coordinate by the width of the texture and
adding the X coordinate.
*/
return y * TEX_SIZE + x ;
}
inline float idToFloat ( int x, int y )
{
/*
Convert a coordinate pair within the texture to a float
by putting one coordinate into the integer part and the
other into the fraction so we can retrieve Y using floor()
and X using fract() to recover them later on inside the shader.
*/
return ((float) idToIndex ( x, y )) / (float)TEX_SIZE ;
}
void keybd ( unsigned char, int, int )
{
@@ -122,7 +151,7 @@ void initGLcontext ( int argc, char **argv,
glutInit ( &argc, argv ) ;
glutInitDisplayMode ( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE ) ;
glutInitWindowSize ( win_width, win_height ) ;
glutCreateWindow ( "Bullet GPU Physics Demo. http://bullet.sf.net" ) ;
glutCreateWindow ( "Shader Math Demo" ) ;
glutDisplayFunc ( display ) ;
glutKeyboardFunc ( keybd ) ;
glutReshapeFunc ( reshape ) ;
@@ -146,6 +175,7 @@ void initMotionTextures ()
velocity = NULL ;
rotvelocity = NULL ;
force = NULL ;
new_force = NULL ;
massSizeX = NULL ;
collisions = NULL ;
}
@@ -154,8 +184,9 @@ void initMotionTextures ()
velocity = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
rotvelocity = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
force = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
new_force = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
massSizeX = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
collisions = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 4, FBO_FLOAT ) ;
collisions = new FrameBufferObject ( TEX_SIZE, TEX_SIZE, 3, FBO_FLOAT ) ;
}
positionData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
@@ -165,7 +196,6 @@ void initMotionTextures ()
float *rotvelocityData ;
float *forceData ;
float *massSizeXData ;
float *collisionData ;
if ( debugOpt == DRAW_WITHOUT_PHYSICS )
{
@@ -181,56 +211,63 @@ void initMotionTextures ()
rotvelocityData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
forceData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
massSizeXData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
collisionData = new float [ TEX_SIZE * TEX_SIZE * 4 ] ;
collisionData = new float [ TEX_SIZE * TEX_SIZE * 3 ] ;
}
/* 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++ )
for ( int y = 0 ; y < TEX_SIZE ; y++ )
for ( int x = 0 ; x < TEX_SIZE ; x++ )
{
/*
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) ;
positionData [ idToIndex(x,y) * 3 + 0 ] = 5.0f * (float) (x - TEX_SIZE/2) ;
positionData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ; // 10.0f ;
positionData [ idToIndex(x,y) * 3 + 2 ] = 5.0f * (float) (y - TEX_SIZE/2) ;
/* 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 ;
rotationData [ idToIndex(x,y) * 3 + 0 ] = 0.0f ;
rotationData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ;
rotationData [ idToIndex(x,y) * 3 + 2 ] = 0.0f ;
if ( debugOpt != DRAW_WITHOUT_PHYSICS )
{
/* Random (but predominantly upwards) velocities. */
velocityData [ (i*TEX_SIZE + j) * 3 + 0 ] = frand ( 10.0f ) - 5.0f;
velocityData [ (i*TEX_SIZE + j) * 3 + 1 ] = frand ( 100.0f ) ;
velocityData [ (i*TEX_SIZE + j) * 3 + 2 ] = frand ( 10.0f ) - 5.0f;
if(irand(8)==0)
{
velocityData [ idToIndex(x,y) * 3 + 0 ] = frand ( 1.0f ) ;
velocityData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ;
velocityData [ idToIndex(x,y) * 3 + 2 ] = frand ( 1.0f ) ;
}
else
{
velocityData [ idToIndex(x,y) * 3 + 0 ] = 0.0f ; //frand ( 10.0f ) - 5.0f;
velocityData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ; //frand ( 100.0f ) ;
velocityData [ idToIndex(x,y) * 3 + 2 ] = 0.0f ; //frand ( 10.0f ) - 5.0f;
}
/* 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 ) ;
rotvelocityData [ idToIndex(x,y) * 3 + 0 ] = 0.0f ; //frand ( 3.0f ) ;
rotvelocityData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ; //frand ( 3.0f ) ;
rotvelocityData [ idToIndex(x,y) * 3 + 2 ] = 0.0f ; //frand ( 3.0f ) ;
/* 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 ;
/* Zero forces */
forceData [ idToIndex(x,y) * 3 + 0 ] = 0.0f ;
forceData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ;
forceData [ idToIndex(x,y) * 3 + 2 ] = 0.0f ;
/* One kg in weight each */
massSizeXData [ (i*TEX_SIZE + j) * 3 + 0 ] = 0.0005f ; /* Mass */
massSizeXData [ (i*TEX_SIZE + j) * 3 + 1 ] = 1.0f ; /* Radius */
massSizeXData [ (i*TEX_SIZE + j) * 3 + 2 ] = 0.0f ; /* Unused */
/* One kg each */
massSizeXData [ idToIndex(x,y) * 3 + 0 ] = 0.05f ; /* Mass */
massSizeXData [ idToIndex(x,y) * 3 + 1 ] = 1.0f ; /* Radius */
massSizeXData [ idToIndex(x,y) * 3 + 2 ] = 0.0f ; /* Unused */
/* Everyone collides with object 0, 1 and 2 */
/*SJB*/
collisionData [ (i*TEX_SIZE + j) * 3 + 0 ] = idToFloat ( 20, 20 ) ;
collisionData [ (i*TEX_SIZE + j) * 3 + 1 ] = idToFloat ( 20, 100 ) ;
collisionData [ (i*TEX_SIZE + j) * 3 + 2 ] = idToFloat ( 100, 20 ) ;
collisionData [ (i*TEX_SIZE + j) * 3 + 3 ] = idToFloat ( 100, 100 ) ;
/* Zero out collision data */
collisionData [ idToIndex(x,y) * 3 + 0 ] = 0.0f ;
collisionData [ idToIndex(x,y) * 3 + 1 ] = 0.0f ;
collisionData [ idToIndex(x,y) * 3 + 2 ] = 0.0f ;
}
}
@@ -241,19 +278,18 @@ void initMotionTextures ()
so put it far away and stop it from moving around.
*/
positionData [ 0 ] = 10.0f ;
positionData [ 1 ] = 10.0f ;
positionData [ 2 ] = 10.0f ;
positionData [ 0 ] = 1000000000.0f ;
positionData [ 1 ] = 1000000000.0f ;
positionData [ 2 ] = 1000000000.0f ;
velocityData [ 0 ] = 0.0f ;
velocityData [ 1 ] = 0.0f ;
velocityData [ 2 ] = 0.0f ;
massSizeXData [ 0 ] = 10000000.0f ; /* Mass */
massSizeXData [ 0 ] = 10000000.0f ; /* Mass */
massSizeXData [ 1 ] = 0.00000001f ; /* Radius */
massSizeXData [ 2 ] = 0.0f ; /* Unused */
collisionData [ 0 ] = 128.5 ; /* Not collide with self! */
collisionData [ 1 ] = 128.5 ;
collisionData [ 2 ] = 128.5 ;
collisionData [ 3 ] = 128.5 ;
massSizeXData [ 2 ] = 0.0f ; /* Unused */
collisionData [ 0 ] = 0.0f ;
collisionData [ 1 ] = 0.0f ;
collisionData [ 2 ] = 0.0f ;
}
/* Initialise the textures */
@@ -267,9 +303,12 @@ void initMotionTextures ()
velocity -> fillTexture ( velocityData ) ;
rotvelocity -> fillTexture ( rotvelocityData ) ;
force -> fillTexture ( forceData ) ;
new_force -> fillTexture ( forceData ) ;
massSizeX -> fillTexture ( massSizeXData ) ;
collisions -> fillTexture ( collisionData ) ;
}
glGenQueriesARB ( NUM_CUBES, queries ) ;
}
@@ -325,44 +364,32 @@ void initPhysicsShaders ()
"PositionGenerator Frag Shader" ) ;
assert ( positionGenerator -> compiledOK () ) ;
collisionGenerator = new GLSL_ShaderPair (
"CollisionGenerator",
NULL,
"collisionShader.frag" ) ;
assert ( collisionGenerator -> compiledOK () ) ;
forceGenerator = new GLSL_ShaderPair (
"ForceGenerator",
NULL, NULL,
"uniform sampler2D force ;"
"uniform sampler2D position ;"
"uniform sampler2D collisions ;"
"void main() {"
" vec3 pos = texture2D ( position , gl_TexCoord[0].st ).xyz ;"
" vec4 coll = texture2D ( collisions, gl_TexCoord[0].st ).xyzw ;"
" vec2 ctc ;"
" vec3 rel ;"
" float lrel ;"
" vec3 force = vec3 ( 0.0, 0.0, 0.0 ) ;"
/* First 'collision' */
" ctc = vec2 ( coll.x / 256.0, coll.x ) ;"
" rel = pos - texture2D ( position, ctc ).xyz ;"
" lrel = max ( length ( rel ), 0.001 ) ;"
" force += (rel/lrel) * -1.0 / (lrel) ;"
/* Second 'collision' */
" ctc = vec2 ( coll.y / 256.0, coll.y ) ;"
" rel = pos - texture2D ( position, ctc ).xyz ;"
" lrel = max ( length ( rel ), 0.001 ) ;"
" force += (rel/lrel) * -1.0 / (lrel) ;"
/* Third 'collision' */
" ctc = vec2 ( coll.z / 256.0, coll.z ) ;"
" rel = pos - texture2D ( position, ctc ).xyz ;"
" lrel = max ( length ( rel ), 0.001 ) ;"
" force += (rel/lrel) * -1.0 / (lrel) ;"
/* Fourth 'collision' */
" ctc = vec2 ( coll.w / 256.0, coll.w ) ;"
" rel = pos - texture2D ( position, ctc ).xyz ;"
" lrel = max ( length ( rel ), 0.001 ) ;"
" force += (rel/lrel) * -1.0 / (lrel) ;"
/* Write out results */
" gl_FragColor = vec4 ( force, 1.0 ) ;"
" vec3 last_force = texture2D ( force , gl_TexCoord[0].st ).xyz ;"
" vec2 id = texture2D ( collisions, gl_TexCoord[0].st ).xy ;"
" vec3 pos = texture2D ( position , gl_TexCoord[0].st ).xyz ;"
" vec3 rel = pos - texture2D ( position, id ).xyz ;"
" float lrel = max ( length ( rel ), 0.001 ) ;"
" gl_FragColor = vec4 ( last_force + (rel / lrel) / lrel, 1.0 ) ;"
"}",
"ForceCollisionGenerator Frag Shader" ) ;
"ForceGenerator Frag Shader" ) ;
assert ( forceGenerator -> compiledOK () ) ;
grndCollisionGenerator = new GLSL_ShaderPair (
"GroundCollisionGenerator",
NULL, NULL,
@@ -371,7 +398,7 @@ void initPhysicsShaders ()
"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 *= vec3(0.90,-0.90,0.90) ;"
" if ( pos [ 1 ] < 0.0 ) vel.y = abs(vel.y) ;"
" gl_FragColor = vec4 ( vel, 1.0 ) ; }",
"GroundCollisionGenerator Frag Shader" ) ;
assert ( grndCollisionGenerator -> compiledOK () ) ;
@@ -392,8 +419,8 @@ void initCubeVBO ()
lengths [ k ] = VERTS_PER_STRIP ;
}
for ( int i = 0 ; i < (noVertexTextureSupport ? 1 : TEX_SIZE) ; i++ )
for ( int j = 0 ; j < (noVertexTextureSupport ? 1 : TEX_SIZE) ; j++ )
for ( int y = 0 ; y < (noVertexTextureSupport ? 1 : TEX_SIZE) ; y++ )
for ( int x = 0 ; x < (noVertexTextureSupport ? 1 : TEX_SIZE) ; x++ )
{
/*
I use the colour data to set which cube is which in
@@ -402,10 +429,10 @@ void initCubeVBO ()
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 ;
*t++ = ((float)x+0.5f)/(float)TEX_SIZE ;
*t++ = ((float)y+0.5f)/(float)TEX_SIZE ;
if ( (i==20||i==100) && (j==20||j==100) )
if ( (x==20||x==100) && (y==20||y==100) )
{
*c++ = 1.0f ;
*c++ = 0.0f ;
@@ -425,9 +452,9 @@ void initCubeVBO ()
if ( debugOpt == DRAW_WITHOUT_SHADERS )
{
dx = 5.0f * (float) (TEX_SIZE/2 - i) ;
dx = 5.0f * (float) (TEX_SIZE/2 - x) ;
dy = 10.0f ;
dz = 5.0f * (float) (TEX_SIZE/2 - j) ;
dz = 5.0f * (float) (TEX_SIZE/2 - y) ;
}
else
{
@@ -478,9 +505,9 @@ void initCubeVBO ()
cubeShader = NULL ;
else
{
//the filenames have additional path to make it easier for some platforms
if ( noVertexTextureSupport )
cubeShader = new GLSL_ShaderPair ( "CubeShader", "cubeShaderNoTexture.vert",
cubeShader = new GLSL_ShaderPair ( "CubeShader",
"cubeShaderNoTexture.vert",
"cubeShader.frag" ) ;
else
cubeShader = new GLSL_ShaderPair ( "CubeShader", "cubeShader.vert",
@@ -501,6 +528,8 @@ void drawCubesTheHardWay ()
float p1 = positionData [ 1 ] ;
float p2 = positionData [ 2 ] ;
glFlush();
restoreFrameBuffer () ;
position -> fetchTexture ( positionData ) ;
rotation -> fetchTexture ( rotationData ) ;
@@ -527,19 +556,20 @@ void drawCubesTheHardWay ()
glBindBufferARB ( GL_ARRAY_BUFFER_ARB, vbo_vx ) ;
glVertexPointer ( 3, GL_FLOAT, 0, vbo_vx ? NULL : vertices ) ;
for ( int i = 0 ; i < TEX_SIZE ; i++ )
for ( int j = 0 ; j < TEX_SIZE ; j++ )
for ( int y = 0 ; y < TEX_SIZE ; y++ )
for ( int x = 0 ; x < TEX_SIZE ; x++ )
{
float *pos = & positionData [ (i*TEX_SIZE + j) * 3 ] ;
float *rot = & rotationData [ (i*TEX_SIZE + j) * 3 ] ;
float *pos = & positionData [ idToIndex ( x, y ) * 3 ] ;
float *rot = & rotationData [ idToIndex ( x, y ) * 3 ] ;
glPushMatrix () ;
glTranslatef ( pos [ 0 ], pos [ 1 ], pos [ 2 ] ) ;
glRotatef ( rot [ 0 ] * 180.0f / 3.14159f, 0, 1, 0 ) ;
glRotatef ( rot [ 1 ] * 180.0f / 3.14159f, 1, 0, 0 ) ;
glRotatef ( rot [ 2 ] * 180.0f / 3.14159f, 0, 0, 1 ) ;
glMultiDrawArraysEXT ( GL_TRIANGLE_STRIP, (GLint*)starts, (GLint*)lengths,
STRIPS_PER_CUBE ) ;
glMultiDrawArraysEXT ( GL_TRIANGLE_STRIP, (GLint*)starts,
(GLint*)lengths,
STRIPS_PER_CUBE ) ;
glPopMatrix () ;
}
@@ -592,9 +622,11 @@ void drawCubes ()
1.0f / ((float)win_width/(float)win_height),
1.0f, 1000000.0f) ;
/* Set up camera position */
glMatrixMode ( GL_MODELVIEW ) ;
glLoadIdentity () ;
glTranslatef ( 10.0, -100.0, -500.0 ) ;
glTranslatef ( 1.25f, -12.5f, -60.0f ) ; // 10.0, -100.0, -500.0 ) ;
glRotatef ( 20.0, 1.0, 0.0, 0.0 ) ;
glEnable ( GL_DEPTH_TEST ) ;
@@ -611,69 +643,174 @@ void drawCubes ()
}
void display ( void )
void runCollisionDetection ()
{
FrameBufferObject *tmp ;
FrameBufferObject *SCM = old ;
FrameBufferObject *DCM = collisions ;
static unsigned int numHits [ NUM_CUBES ] ;
static float texCoordIdent [ NUM_CUBES * 2 ] ;
static int firsttime = true ;
if ( firsttime )
{
firsttime = false ;
for ( int y = 0 ; y < TEX_SIZE ; y++ )
for ( int x = 0 ; x < TEX_SIZE ; x++ )
{
texCoordIdent [ idToIndex ( x, y ) * 2 + 0 ] =
(((float) x) + 0.5 )/(float)TEX_SIZE ;
texCoordIdent [ idToIndex ( x, y ) * 2 + 1 ] =
(((float) y) + 0.5 )/(float)TEX_SIZE ;
}
}
/* Mark all polygons 'needed' */
memset ( numHits, 0xFF, NUM_CUBES * sizeof(unsigned int) ) ;
/* Fill SCM with big numbers */
glClearColor ( 1.0f, 1.0f, 1.0f, 1.0f ) ;
SCM -> prepare ( true ) ;
glClearColor ( 0.0f, 0.0f, 0.0f, 0.0f ) ;
force -> prepare ( true ) ; /* Zero out all of the forces. */
bool allDone ;
while ( true )
{
collisionGenerator -> use () ;
collisionGenerator -> applyTexture ( "position" , position, 0 ) ;
collisionGenerator -> applyTexture ( "old_collisions", SCM , 1 ) ;
/* Fill DCM with zeroes */
DCM -> prepare ( true ) ;
for ( int i = 0 ; i < NUM_CUBES ; i++ )
{
if ( numHits [ i ] != 0 )
{
glMultiTexCoord2fv ( GL_TEXTURE0 + 1, & ( texCoordIdent [ i * 2 ] )) ;
glBeginQueryARB ( GL_SAMPLES_PASSED_ARB, queries [ i ] ) ;
DCM -> fill () ;
glEndQueryARB ( GL_SAMPLES_PASSED_ARB ) ;
}
}
allDone = true ;
int numCollisionPairs = 0 ;
for ( int i = 0 ; i < NUM_CUBES ; i++ )
{
if ( numHits [ i ] == 0 ) continue ;
GLuint sampleCount ;
glGetQueryObjectuivARB ( queries[i], GL_QUERY_RESULT_ARB,
&sampleCount ) ;
numHits [ i ] = sampleCount ;
numCollisionPairs += sampleCount ;
if ( sampleCount != 0 )
allDone = false ;
}
if (numCollisionPairs > 0 )
fprintf ( stderr, "%d ", numCollisionPairs ) ;
if ( allDone )
break ;
forceGenerator -> use () ;
forceGenerator -> applyTexture ( "position" , position , 0 ) ;
forceGenerator -> applyTexture ( "force" , force , 1 ) ;
forceGenerator -> applyTexture ( "collisions", DCM , 2 ) ;
new_force -> paint () ;
tmp = new_force ;
new_force = force ;
force = tmp ;
tmp = DCM ;
DCM = SCM ;
SCM = tmp ;
}
}
void runPhysics ()
{
FrameBufferObject *tmp ;
/* Do some simple physics calculations in four stages */
/* Copy old velocity into old. */
tmp = old ;
old = velocity ;
velocity = tmp ;
velocityGenerator -> use () ;
velocityGenerator -> applyTexture ( "old_velocity", old , 0 ) ;
velocityGenerator -> applyTexture ( "force" , force , 1 ) ;
velocityGenerator -> applyTexture ( "massSizeX" , massSizeX, 2 ) ;
velocityGenerator -> setUniform4f ( "g_dt", 0.0f, /*-9.8f */ 0.0f, 0.0f, TIMESTEP ) ;
velocity -> paint () ;
/* Copy old position into old. */
tmp = old ;
old = position ;
position = tmp ;
positionGenerator -> use () ;
positionGenerator -> applyTexture ( "old_position", old , 0 ) ;
positionGenerator -> applyTexture ( "velocity" , velocity, 1 ) ;
positionGenerator -> setUniform1f ( "delta_T", TIMESTEP ) ;
position -> paint () ;
/* Copy old velocity into old. */
tmp = old ;
old = velocity ;
velocity = tmp ;
grndCollisionGenerator -> use () ;
grndCollisionGenerator -> applyTexture ( "position" , position, 0 ) ;
grndCollisionGenerator -> applyTexture ( "old_velocity", old , 1 ) ;
velocity -> paint () ;
/* Copy old rotation into old. */
tmp = old ;
old = rotation ;
rotation = tmp ;
positionGenerator -> use () ;
positionGenerator -> applyTexture ( "old_position", old , 0 ) ;
positionGenerator -> applyTexture ( "velocity" , rotvelocity, 1 ) ;
positionGenerator -> setUniform1f ( "delta_T", TIMESTEP ) ;
rotation -> paint () ;
restoreFrameBuffer () ;
}
void display ( void )
{
if ( debugOpt != DRAW_WITHOUT_SHADERS &&
debugOpt != DRAW_WITHOUT_PHYSICS )
{
/* Do some simple physics calculations in four stages */
forceGenerator -> use () ;
forceGenerator -> applyTexture ( "position" , position , 0 ) ;
forceGenerator -> applyTexture ( "collisions", collisions, 1 ) ;
force -> paint () ;
/* Copy old velocity into old. */
tmp = old ;
old = velocity ;
velocity = tmp ;
velocityGenerator -> use () ;
velocityGenerator -> applyTexture ( "old_velocity", old , 0 ) ;
velocityGenerator -> applyTexture ( "force" , force , 1 ) ;
velocityGenerator -> applyTexture ( "massSizeX" , massSizeX, 2 ) ;
velocityGenerator -> setUniform4f ( "g_dt", 0.0f, -9.8f, 0.0f, TIMESTEP ) ;
velocity -> paint () ;
/* Copy old position into old. */
tmp = old ;
old = position ;
position = tmp ;
positionGenerator -> use () ;
positionGenerator -> applyTexture ( "old_position", old , 0 ) ;
positionGenerator -> applyTexture ( "velocity" , velocity, 1 ) ;
positionGenerator -> setUniform1f ( "delta_T", TIMESTEP ) ;
position -> paint () ;
/* Copy old velocity into old. */
tmp = old ;
old = velocity ;
velocity = tmp ;
grndCollisionGenerator -> use () ;
grndCollisionGenerator -> applyTexture ( "position" , position, 0 ) ;
grndCollisionGenerator -> applyTexture ( "old_velocity", old , 1 ) ;
velocity -> paint () ;
/* Copy old rotation into old. */
tmp = old ;
old = rotation ;
rotation = tmp ;
positionGenerator -> use () ;
positionGenerator -> applyTexture ( "old_position", old , 0 ) ;
positionGenerator -> applyTexture ( "velocity" , rotvelocity, 1 ) ;
positionGenerator -> setUniform1f ( "delta_T", TIMESTEP ) ;
rotation -> paint () ;
/* Now render the scene using the results */
restoreFrameBuffer () ;
runCollisionDetection () ;
runPhysics () ;
}
/* Now render the scene using the results */
glViewport ( 0, 0, win_width, win_height ) ;
drawCubes () ;
@@ -701,7 +838,7 @@ void help ()
int main ( int argc, char **argv )
{
bool disableVertexTextureSupport = true ;
bool disableVertexTextureSupport = false ;
debugOpt = DRAW_ALL ;
for ( int i = 1 ; i < argc ; i++ )

30
Extras/GPUphysics/collisionShader.frag Normal file
View File

@@ -0,0 +1,30 @@
uniform sampler2D position ;
uniform sampler2D old_collisions ;
void main()
{
vec2 my_id = gl_TexCoord[0].st ;
vec2 pr_id = gl_TexCoord[1].st ;
/* Object colliding with itself */
if ( length ( my_id - pr_id ) < 0.05) discard ;
vec2 last_id = texture2D ( old_collisions, my_id ).xy ;
/* Object collision that will already have been dealt with */
if ( pr_id.y >= last_id.y ) discard ;
if ( pr_id.y == last_id.y && pr_id.x >= last_id.y) discard ;
vec3 my_pos = texture2D ( position, my_id ).xyz ;
vec3 pr_pos = texture2D ( position, pr_id ).xyz ;
/* Objects that don't actually collide */
if ( length ( my_pos - pr_pos ) >= 2.0 ) discard ;
gl_FragColor = vec4 ( pr_id, 0, 1 ) ;
}

7
Extras/GPUphysics/fboSupport.cpp
View File

@@ -335,12 +335,14 @@ void FrameBufferObject::fillTexture ( float *data )
}
void FrameBufferObject::paint ()
void FrameBufferObject::prepare ( bool clear )
{
makeDestination () ;
glViewport ( 0, 0, width, height ) ;
if ( clear ) glClear ( GL_COLOR_BUFFER_BIT ) ;
glMatrixMode ( GL_PROJECTION ) ;
glLoadIdentity () ;
glOrtho ( -1, 1, -1, 1, -1, 1 ) ;
@@ -351,8 +353,11 @@ void FrameBufferObject::paint ()
glDisable ( GL_DEPTH_TEST ) ;
glDisable ( GL_CULL_FACE ) ;
glDisable ( GL_BLEND ) ;
}
void FrameBufferObject::fill ()
{
float s_min = 0.5f / (float) width ;
float s_max = (((float) width) - 0.5f) / (float) width ;
float t_min = 0.5f / (float) height ;

5
Extras/GPUphysics/fboSupport.h
View File

@@ -73,7 +73,10 @@ public:
glBindTexture ( GL_TEXTURE_2D, textureHandle ) ;
}
void paint () ;
void prepare ( bool clear = false ) ;
void fill () ;
void paint ( bool clear = false ) { prepare ( clear ) ; fill () ; }
void fillTexture ( float *data ) ;
void fillTexture ( unsigned short *data ) ;

1
Extras/GPUphysics/shaderSupport.cpp
View File

@@ -6,6 +6,7 @@
"void main()" \
"{" \
" gl_TexCoord[0] = gl_MultiTexCoord0 ;" \
" gl_TexCoord[1] = gl_MultiTexCoord1 ;" \
" gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex ;" \
"}"