axmol/tests/cpp-tests/Source/ChipmunkTestBed/demo/Query.cpp

/* 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 "chipmunk/chipmunk.h"
#include "ChipmunkDemo.h"

static cpVect QUERY_START = {0, 0};

static void update(cpSpace* space, double dt)
{
    cpSpaceStep(space, dt);

    if (ChipmunkDemoRightClick)
    {
        QUERY_START = ChipmunkDemoMouse;
    }

    cpVect start   = QUERY_START;
    cpVect end     = ChipmunkDemoMouse;
    cpFloat radius = 10.0;
    ChipmunkDebugDrawSegment(start, end, RGBAColor(0, 1, 0, 1));

    ChipmunkDemoPrintString("Query: Dist(%f)   Point(%5.2f, %5.2f),\n", cpvdist(start, end), end.x, end.y);

    cpSegmentQueryInfo segInfo = {0};
    if (cpSpaceSegmentQueryFirst(space, start, end, radius, CP_SHAPE_FILTER_ALL, &segInfo))
    {
        cpVect point = segInfo.point;
        cpVect n     = segInfo.normal;

        // Draw blue over the occluded part of the query
        ChipmunkDebugDrawSegment(cpvlerp(start, end, segInfo.alpha), end, RGBAColor(0, 0, 1, 1));

        // Draw a little red surface normal
        ChipmunkDebugDrawSegment(point, cpvadd(point, cpvmult(n, 16)), RGBAColor(1, 0, 0, 1));

        // Draw a little red dot on the hit point.
        ChipmunkDebugDrawDot(3, point, RGBAColor(1, 0, 0, 1));

        ChipmunkDemoPrintString("Segment Query: Dist(%f)   Normal(%5.2f, %5.2f)\n", segInfo.alpha * cpvdist(start, end),
                                n.x, n.y);
    }
    else
    {
        ChipmunkDemoPrintString("Segment Query (None)\n");
    }

    // Draw a fat green line over the unoccluded part of the query
    ChipmunkDebugDrawFatSegment(start, cpvlerp(start, end, segInfo.alpha), radius, RGBAColor(0, 1, 0, 1),
                                LAColor(0, 0));

    cpPointQueryInfo nearestInfo = {0};
    cpSpacePointQueryNearest(space, ChipmunkDemoMouse, 100.0, CP_SHAPE_FILTER_ALL, &nearestInfo);
    if (nearestInfo.shape)
    {
        // Draw a grey line to the closest shape.
        ChipmunkDebugDrawDot(3, ChipmunkDemoMouse, RGBAColor(0.5, 0.5, 0.5, 1.0));
        ChipmunkDebugDrawSegment(ChipmunkDemoMouse, nearestInfo.point, RGBAColor(0.5, 0.5, 0.5, 1.0));

        // Draw a red bounding box around the shape under the mouse.
        if (nearestInfo.distance < 0)
            ChipmunkDebugDrawBB(cpShapeGetBB(nearestInfo.shape), RGBAColor(1, 0, 0, 1));
    }
}

static cpSpace* init(void)
{
    QUERY_START = cpvzero;

    cpSpace* space = cpSpaceNew();
    cpSpaceSetIterations(space, 5);

    {  // add a fat segment
        cpFloat mass   = 1.0f;
        cpFloat length = 100.0f;
        cpVect a = cpv(-length / 2.0f, 0.0f), b = cpv(length / 2.0f, 0.0f);

        cpBody* body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForSegment(mass, a, b, 0.0f)));
        cpBodySetPosition(body, cpv(0.0f, 100.0f));

        cpSpaceAddShape(space, cpSegmentShapeNew(body, a, b, 20.0f));
    }

    {  // add a static segment
        cpSpaceAddShape(space, cpSegmentShapeNew(cpSpaceGetStaticBody(space), cpv(0, 300), cpv(300, 0), 0.0f));
    }

    {  // add a pentagon
        cpFloat mass = 1.0f;

        cpVect verts[5];
        for (int i = 0; i < 5; i++)
        {
            cpFloat angle = -2.0f * CP_PI * i / ((cpFloat)5);
            verts[i]      = cpv(30 * cos(angle), 30 * sin(angle));
        }

        cpBody* body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForPoly(mass, 5, verts, cpvzero, 0.0f)));
        cpBodySetPosition(body, cpv(50.0f, 30.0f));

        cpSpaceAddShape(space, cpPolyShapeNew(body, 5, verts, cpTransformIdentity, 10.0f));
    }

    {  // add a circle
        cpFloat mass = 1.0f;
        cpFloat r    = 20.0f;

        cpBody* body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForCircle(mass, 0.0f, r, cpvzero)));
        cpBodySetPosition(body, cpv(100.0f, 100.0f));

        cpSpaceAddShape(space, cpCircleShapeNew(body, r, cpvzero));
    }

    return space;
}

static void destroy(cpSpace* space)
{
    ChipmunkDemoFreeSpaceChildren(space);
    cpSpaceFree(space);
}

ChipmunkDemo Query = {
    "Segment Query", 1.0 / 60.0, init, update, ChipmunkDemoDefaultDrawImpl, destroy,
};