Box2DTestCPPComplianceShapeCast.cpp

#include <Box2D/Box2D.h>

#include <stdio.h>

void TestCPPComplianceShapeCast()
{
    b2Vec2 m_vAs[b2_maxPolygonVertices];
    int32_t m_countA;
    double m_radiusA;

    b2Vec2 m_vBs[b2_maxPolygonVertices];
    int32_t m_countB;
    double m_radiusB;

    m_vAs[0].Set(-0.5f, 1.0f);
    m_vAs[1].Set(0.5f, 1.0f);
    m_vAs[2].Set(0.0f, 0.0f);
    m_countA = 3;
    m_radiusA = b2_polygonRadius;

    m_vBs[0].Set(-0.5f, -0.5f);
    m_vBs[1].Set(0.5f, -0.5f);
    m_vBs[2].Set(0.5f, 0.5f);
    m_vBs[3].Set(-0.5f, 0.5f);
    m_countB = 4;
    m_radiusB = b2_polygonRadius;

    b2Transform transformA;
    transformA.p = b2Vec2(0.0f, 0.25f);
    transformA.q.SetIdentity();

    b2Transform transformB;
    transformB.SetIdentity();

    b2ShapeCastInput input;
    input.proxyA.Set(m_vAs, m_countA, m_radiusA);
    input.proxyB.Set(m_vBs, m_countB, m_radiusB);
    input.transformA = transformA;
    input.transformB = transformB;
    input.translationB.Set(8.0f, 0.0f);

    b2ShapeCastOutput output;

    bool hit = b2ShapeCast(&output, &input);

    b2Transform transformB2;
    transformB2.q = transformB.q;
    transformB2.p = transformB.p + output.lambda * input.translationB;

    b2DistanceInput distanceInput;
    distanceInput.proxyA.Set(m_vAs, m_countA, m_radiusA);
    distanceInput.proxyB.Set(m_vBs, m_countB, m_radiusB);
    distanceInput.transformA = transformA;
    distanceInput.transformB = transformB2;
    distanceInput.useRadii = false;
    b2SimplexCache simplexCache;
    simplexCache.count = 0;
    b2DistanceOutput distanceOutput;

    b2Distance(&distanceOutput, &simplexCache, &distanceInput);

    printf("hit = %s, iters = %d, lambda = %g, distance = %.15f", hit ? "true" : "false", output.iterations, output.lambda, distanceOutput.distance);
}