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/* 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 <math.h>
#include "chipmunk.h"
#include "drawSpace.h"
#include "ChipmunkDemo.h"
static cpSpace *space;
// Init is called by the demo code to set up the demo.
static cpSpace *
init(void)
{
// Create a space, a space is a simulation world. It simulates the motions of rigid bodies,
// handles collisions between them, and simulates the joints between them.
space = cpSpaceNew();
// Lets set some parameters of the space:
// More iterations make the simulation more accurate but slower
space->iterations = 10;
// These parameters tune the efficiency of the collision detection.
// For more info: http://code.google.com/p/chipmunk-physics/wiki/cpSpace
cpSpaceResizeStaticHash(space, 30.0f, 1000);
cpSpaceResizeActiveHash(space, 30.0f, 1000);
// Give it some gravity
space->gravity = cpv(0, -100);
// Create A ground segment along the bottom of the screen
// By attaching it to &space->staticBody instead of a body, we make it a static shape.
cpShape *ground = cpSegmentShapeNew(&space->staticBody, cpv(-320,-240), cpv(320,-240), 0.0f);
// Set some parameters of the shape.
// For more info: http://code.google.com/p/chipmunk-physics/wiki/cpShape
ground->e = 1.0f; ground->u = 1.0f;
ground->layers = NOT_GRABABLE_MASK; // Used by the Demo mouse grabbing code
// Add the shape to the space as a static shape
// If a shape never changes position, add it as static so Chipmunk knows it only needs to
// calculate collision information for it once when it is added.
// Do not change the postion of a static shape after adding it.
cpSpaceAddShape(space, ground);
// Add a moving circle object.
cpFloat radius = 15.0f;
cpFloat mass = 10.0f;
// This time we need to give a mass and moment of inertia when creating the circle.
cpBody *ballBody = cpBodyNew(mass, cpMomentForCircle(mass, 0.0f, radius, cpvzero));
// Set some parameters of the body:
// For more info: http://code.google.com/p/chipmunk-physics/wiki/cpBody
ballBody->p = cpv(0, -240 + radius+50);
ballBody->v = cpv(0, -20);
// Add the body to the space so it will be simulated and move around.
cpSpaceAddBody(space, ballBody);
// Add a circle shape for the ball.
// Shapes are always defined relative to the center of gravity of the body they are attached to.
// When the body moves or rotates, the shape will move with it.
// Additionally, all of the cpSpaceAdd*() functions return the thing they added so you can create and add in one go.
cpShape *ballShape = cpSpaceAddShape(space, cpCircleShapeNew(ballBody, radius, cpvzero));
ballShape->e = 0.0f; ballShape->u = 0.9f;
return space;
}
// Update is called by the demo code each frame.
static void
update(int ticks)
{
// Chipmunk allows you to use a different timestep each frame, but it works much better when you use a fixed timestep.
// An excellent article on why fixed timesteps for game logic can be found here: http://gafferongames.com/game-physics/fix-your-timestep/
cpSpaceStep(space, 1.0f/60.0f);
}
// destroy is called by the demo code to free all the memory we've allocated
static void
destroy(void)
{
cpSpaceFreeChildren(space);
cpSpaceFree(space);
}
chipmunkDemo Simple = {
"Simple",
NULL,
init,
update,
destroy,
};
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