lovr-ODE/tests/collision.cpp

#include <UnitTest++.h>
#include <ode/ode.h>

TEST(test_collision_trimesh_sphere_exact)
{
    /*
     * This tests some extreme cases, where a sphere barely touches some triangles
     * with zero depth.
     */
    
    #ifdef dTRIMESH_GIMPACT
    /*
     * Although GIMPACT is algorithmically able to handle this extreme case,
     * the numerical approximation used for the square root produces inexact results.
     */
    return;
    #endif

    {
        const int VertexCount = 4;
        const int IndexCount = 2*3;
        // this is a square on the XY plane
        /*
           3    2
           +----+
           |   /|
           |  / |
           | /  |
           |/   |
           +----+
           0    1
         */
        float vertices[VertexCount * 3] = {
            -1,-1,0,
            1,-1,0,
            1,1,0,
            -1,1,0
        };
        dTriIndex indices[IndexCount] = {
            0,1,2,
            0,2,3
        };
        
        dTriMeshDataID data = dGeomTriMeshDataCreate();
        dGeomTriMeshDataBuildSingle(data,
                                    vertices,
                                    3 * sizeof(float),
                                    VertexCount,
                                    indices,
                                    IndexCount,
                                    3 * sizeof(dTriIndex));
        dGeomID trimesh = dCreateTriMesh(0, data, 0, 0, 0);
        const dReal radius = 4;
        dGeomID sphere = dCreateSphere(0, radius);
        dContactGeom cg[4];
        int nc;
        dVector3 trinormal = { 0, 0, -1 };

        // Test case: sphere touches the diagonal edge
        dGeomSetPosition(sphere, 0,0,radius);
        nc = dCollide(trimesh, sphere, 4, &cg[0], sizeof cg[0]);
        CHECK_EQUAL(2, nc);
        for (int i=0; i<nc; ++i) {
            CHECK_EQUAL(0, cg[i].depth);
            CHECK_ARRAY_EQUAL(trinormal, cg[i].normal, 3);
        }
        
        // now translate both geoms
        dGeomSetPosition(trimesh, 10,30,40);
        dGeomSetPosition(sphere, 10,30,40+radius);
        // check extreme case, again
        nc = dCollide(trimesh, sphere, 4, &cg[0], sizeof cg[0]);
        CHECK_EQUAL(2, nc);
        for (int i=0; i<nc; ++i) {
            CHECK_EQUAL(0, cg[i].depth);
            CHECK_ARRAY_EQUAL(trinormal, cg[i].normal, 3);
        }
        
        // and now, let's rotate the trimesh, 90 degrees on X
        dMatrix3 rot = { 1, 0, 0, 0,
                         0, 0, -1, 0,
                         0, 1, 0, 0 };
        dGeomSetPosition(trimesh, 10,30,40);
        dGeomSetRotation(trimesh, rot);
        
        dGeomSetPosition(sphere, 10,30-radius,40);
        // check extreme case, again
        nc = dCollide(trimesh, sphere, 4, &cg[0], sizeof cg[0]);
        CHECK_EQUAL(2, nc);
        dVector3 rtrinormal = { 0, 1, 0 };
        for (int i=0; i<nc; ++i) {
            CHECK_EQUAL(0, cg[i].depth);
            CHECK_ARRAY_EQUAL(rtrinormal, cg[i].normal, 3);
        }
    }
}



TEST(test_collision_heightfield_ray_fail)
{
    /*
     * This test demonstrated a bug in the AABB handling of the
     * heightfield.
     */
    {
        // Create quick heightfield with dummy data
        dHeightfieldDataID heightfieldData = dGeomHeightfieldDataCreate();
        unsigned char dataBuffer[16+1] = "1234567890123456";
        dGeomHeightfieldDataBuildByte(heightfieldData, dataBuffer, 0, 4, 4, 4, 4, 1, 0, 0, 0);
        dGeomHeightfieldDataSetBounds(heightfieldData, '0', '9');
	    dGeomID height = dCreateHeightfield(0, heightfieldData, 1);

        // Create ray outside bounds
        dGeomID ray = dCreateRay(0, 20);
        dGeomRaySet(ray, 5, 10, 1, 0, -1, 0);
        dContact contactBuf[10];

        // Make sure it does not crash!
        dCollide(ray, height, 10, &(contactBuf[0].geom), sizeof(dContact));

        dGeomDestroy(height);
        dGeomDestroy(ray);
        dGeomHeightfieldDataDestroy(heightfieldData);
    }
}