Function update

tests/cpp-tests/Source/ChipmunkTestBed/demo/Query.cpp:27–82

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)