/* Copyright (c) 2007 Scott Lembcke *  * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: *  * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. *  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include <stdlib.h>#include <stdio.h>#include <math.h>#include "chipmunk.h"#define SLEEP_TICKS 16extern cpSpace *space;extern cpBody *staticBody;// Iterate over all of the bodies and reset the ones that have fallen offscreen.static voideachBody(cpBody *body, void *unused){	if(body->p.y < -260 || fabsf(body->p.x) > 340){		cpFloat x = rand()/(cpFloat)RAND_MAX*640 - 320;		body->p = cpv(x, 260);	}}void demo3_update(int ticks){	int steps = 1;	cpFloat dt = 1.0f/60.0f/(cpFloat)steps;		for(int i=0; i<steps; i++){		cpSpaceStep(space, dt);		cpSpaceEachBody(space, &eachBody, NULL);	}}#define NUM_VERTS 5void demo3_init(void){	staticBody = cpBodyNew(INFINITY, INFINITY);		cpResetShapeIdCounter();		space = cpSpaceNew();	space->iterations = 5;	space->gravity = cpv(0, -100);		cpSpaceResizeStaticHash(space, 40.0f, 999);	cpSpaceResizeActiveHash(space, 30.0f, 2999);		cpBody *body;	cpShape *shape;		// Create vertexes for a pentagon shape.	cpVect verts[NUM_VERTS];	for(int i=0; i<NUM_VERTS; i++){		cpFloat angle = (cpFloat) (-2*M_PI*i/((cpFloat) NUM_VERTS));		verts[i] = cpv(10*cosf(angle), 10*sinf(angle));	}		// Vertexes for a triangle shape.	cpVect tris[] = {		cpv(-15,-15),		cpv(  0, 10),		cpv( 15,-15),	};	// Create the static triangles.	for(int i=0; i<9; i++){		for(int j=0; j<6; j++){			cpFloat stagger = (j%2)*40;			cpVect offset = cpv(i*80 - 320 + stagger, j*70 - 240);			shape = cpPolyShapeNew(staticBody, 3, tris, offset);			shape->e = 1.0f; shape->u = 1.0f;			cpSpaceAddStaticShape(space, shape);		}	}		// Add lots of pentagons.	for(int i=0; i<300; i++){		body = cpBodyNew(1.0f, cpMomentForPoly(1.0f, NUM_VERTS, verts, cpvzero));		cpFloat x = rand()/(cpFloat)RAND_MAX*640 - 320;		body->p = cpv(x, 350);				cpSpaceAddBody(space, body);		shape = cpPolyShapeNew(body, NUM_VERTS, verts, cpvzero);		shape->e = 0.0f; shape->u = 0.4f;		cpSpaceAddShape(space, shape);	}}