/* 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"extern cpSpace *space;extern cpBody *staticBody;void demo1_update(int ticks){	int steps = 2;	cpFloat dt = 1.0f/60.0f/(cpFloat)steps;		for(int i=0; i<steps; i++){		cpSpaceStep(space, dt);	}}int some_value = 42;static intcollFunc(cpShape *a, cpShape *b, cpContact *contacts, int numContacts, cpFloat normal_coef, void *data){//	int *some_ptr = (int *)data;// Do various things with the contact information. // Make particle effects, estimate the impact damage from the relative velocities, etc.//	for(int i=0; i<numContacts; i++)//		printf("Collision at %s. (%d - %d) %d\n", cpvstr(contacts[i].p), a->collision_type, b->collision_type, *some_ptr);		// Returning 0 will cause the collision to be discarded. This allows you to do conditional collisions.	return 1;}void demo1_init(void){	// Initialize a static body with infinite mass and moment of inertia	// to attach the static geometry to.	staticBody = cpBodyNew(INFINITY, INFINITY);		// Optional. Read the docs to see what this really does.	cpResetShapeIdCounter();		// Create a space and adjust some of it's parameters.	space = cpSpaceNew();	cpSpaceResizeStaticHash(space, 20.0f, 999);	space->gravity = cpv(0, -100);		cpBody *body;	cpShape *shape;		// Vertexes we'll use to create a box.	// Note that the vertexes are in counterclockwise order.	int num = 4;	cpVect verts[] = {		cpv(-15,-15),		cpv(-15, 15),		cpv( 15, 15),		cpv( 15,-15),	};		// Create some segments around the edges of the screen.	shape = cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(-320,240), 0.0f);	shape->e = 1.0f; shape->u = 1.0f;	cpSpaceAddStaticShape(space, shape);	shape = cpSegmentShapeNew(staticBody, cpv(320,-240), cpv(320,240), 0.0f);	shape->e = 1.0f; shape->u = 1.0f;	cpSpaceAddStaticShape(space, shape);	shape = cpSegmentShapeNew(staticBody,cpv(-320,-240), cpv(320,-240), 0.0f);	shape->e = 1.0f; shape->u = 1.0f;	cpSpaceAddStaticShape(space, shape);	// Create the stair steps.	for(int i=0; i<50; i++){		int j = i + 1;		cpVect a = cpv(i*10 - 320, i*-10 + 240);		cpVect b = cpv(j*10 - 320, i*-10 + 240);		cpVect c = cpv(j*10 - 320, j*-10 + 240);				shape = cpSegmentShapeNew(staticBody, a, b, 0.0f);		shape->e = 1.0f; shape->u = 1.0f;		cpSpaceAddStaticShape(space, shape);				shape = cpSegmentShapeNew(staticBody, b, c, 0.0f);		shape->e = 1.0f; shape->u = 1.0f;		cpSpaceAddStaticShape(space, shape);	}		// Create a box and initialize some of its parameters.	body = cpBodyNew(1.0f, cpMomentForPoly(1.0f, num, verts, cpvzero));	body->p = cpv(-280, 240);	cpSpaceAddBody(space, body);	shape = cpPolyShapeNew(body, num, verts, cpvzero);	shape->e = 0.0f; shape->u = 1.5f;	shape->collision_type = 1;	cpSpaceAddShape(space, shape);		// Add a collision callback between objects of the default type and the box.	cpSpaceAddCollisionPairFunc(space, 1, 0, &collFunc, &some_value);}