Ejemplo n.º 1
0
        /// Get the inverse of this matrix as a 2-by-2.
        /// Returns the zero matrix if singular.
        public b2Mat33 GetInverse22(b2Mat33 M)
        {
            float a = ex.x, b = ey.x, c = ex.y, d = ey.y;
            float det = a * d - b * c;
            if (det != 0.0f)
            {
                det = 1.0f / det;
            }

            M.ex.x = det * d; M.ey.x = -det * b; M.ex.z = 0.0f;
            M.ex.y = -det * c; M.ey.y = det * a; M.ey.z = 0.0f;
            M.ez.x = 0.0f; M.ez.y = 0.0f; M.ez.z = 0.0f;
            return (M);
        }
Ejemplo n.º 2
0
 void _setMat33Scale(ref b2Mat33 mat, float xfactor, float yfactor)
 {
     mat.SetZero();
     mat.ex.x = xfactor;
     mat.ey.y = yfactor;
     mat.ez.z = 1;
 }
Ejemplo n.º 3
0
 void _setMat33Translation(ref b2Mat33 mat, cpVect t)
 {
     mat.SetZero();
     mat.ex.x = 1;
     mat.ey.y = 1;
     mat.ez.x = t.x;
     mat.ez.y = t.y;
     mat.ez.z = 1;
 }
Ejemplo n.º 4
0
 void _setMat33Rotation(ref b2Mat33 mat, float angle)
 {
     mat.SetZero();
     float c = cp.cpfcos(angle), s = cp.cpfsin(angle);
     mat.ex.x = c; mat.ey.x = -s;
     mat.ex.y = s; mat.ey.y = c;
     mat.ez.z = 1;
 }
Ejemplo n.º 5
0
 b2Mat33 _b2Mul(b2Mat33 B, b2Mat33 A)
 {
     return new b2Mat33(b2Mul(A, B.ex), b2Mul(A, B.ey), b2Mul(A, B.ez));
 }
Ejemplo n.º 6
0
 cpVect _b2Mul(b2Mat33 A, cpVect v2)
 {
     b2Vec3 v = new b2Vec3(v2.x, v2.y, 1);
     b2Vec3 r = v.x * A.ex + v.y * A.ey + v.z * A.ez;
     return new cpVect(r.x, r.y);
 }
Ejemplo n.º 7
0
        public void updateUVs(float aspect)
        {
            //set up vertices

            float hx = 0.5f * aspect;
            float hy = 0.5f;

            cpVect[] verts = new cpVect[4];
            verts[0] = new cpVect(-hx, -hy);
            verts[1] = new cpVect(hx, -hy);
            verts[2] = new cpVect(hx, hy);
            verts[3] = new cpVect(-hx, hy);

            b2Mat33 r = new b2Mat33(), s = new b2Mat33();
            _setMat33Rotation(ref r, Angle);
            _setMat33Scale(ref s, Scale, Scale);
            b2Mat33 m = _b2Mul(r, s);

            for (int i = 0; i < 4; i++)
            {
                verts[i] = _b2Mul(m, verts[i]);
                verts[i] = cpVect.cpvadd(verts[i], Center);
            }

            //set up uvs

            cpVect[] uvs = new cpVect[4];
            uvs[0] = new cpVect(0, 0);
            uvs[1] = new cpVect(1, 0);
            uvs[2] = new cpVect(1, 1);
            uvs[3] = new cpVect(0, 1);

            //set up arrays for rendering

            NumPoints = 4;
            NumIndices = 6;

            //if (points!=null) delete[] points;
            //if (uvCoords) delete[] uvCoords;
            //if (indices) delete[] indices;

            Points = new float[2 * NumPoints];
            UvCoords = new float[2 * NumPoints];
            Indices = new short[NumIndices];

            for (int i = 0; i < NumPoints; i++)
            {
                Points[2 * i + 0] = verts[i].x;
                Points[2 * i + 1] = verts[i].y;
                UvCoords[2 * i + 0] = uvs[i].x;
                UvCoords[2 * i + 1] = uvs[i].y;
            }

            Indices[0] = 0;
            Indices[1] = 1;
            Indices[2] = 2;
            Indices[3] = 2;
            Indices[4] = 3;
            Indices[5] = 0;
        }
Ejemplo n.º 8
0
 /// Multiply a matrix times a vector.
 public b2Vec3 b2Mul(b2Mat33 A, b2Vec3 v)
 {
     return v.x * A.ex + v.y * A.ey + v.z * A.ez;
 }