Esempio n. 1
0
void AffineUnit::calculate_matrix(
	double in_x1,
	double in_y1,
	double in_x2,
	double in_y2,
	double out_x1,
	double out_y1,
	double out_x2,
	double out_y2,
	double out_x3,
	double out_y3,
	double out_x4,
	double out_y4,
	AffineMatrix *result)
{
	AffineMatrix matrix;
	double scalex;
	double scaley;

	scalex = scaley = 1.0;

	if((in_x2 - in_x1) > 0)
		scalex = 1.0 / (double)(in_x2 - in_x1);

	if((in_y2 - in_y1) > 0)
		scaley = 1.0 / (double)(in_y2 - in_y1);

// Determine the perspective transform that maps from
// the unit cube to the transformed coordinates
	double dx1, dx2, dx3, dy1, dy2, dy3;
	double det1, det2;

	dx1 = out_x2 - out_x4;
	dx2 = out_x3 - out_x4;
	dx3 = out_x1 - out_x2 + out_x4 - out_x3;

	dy1 = out_y2 - out_y4;
	dy2 = out_y3 - out_y4;
	dy3 = out_y1 - out_y2 + out_y4 - out_y3;

//  Is the mapping affine?
	if((dx3 == 0.0) && (dy3 == 0.0))
	{
		matrix.values[0][0] = out_x2 - out_x1;
		matrix.values[0][1] = out_x4 - out_x2;
		matrix.values[0][2] = out_x1;
		matrix.values[1][0] = out_y2 - out_y1;
		matrix.values[1][1] = out_y4 - out_y2;
		matrix.values[1][2] = out_y1;
		matrix.values[2][0] = 0.0;
		matrix.values[2][1] = 0.0;
	}
	else
	{
		det1 = dx3 * dy2 - dy3 * dx2;
		det2 = dx1 * dy2 - dy1 * dx2;
		matrix.values[2][0] = det1 / det2;
		det1 = dx1 * dy3 - dy1 * dx3;
		det2 = dx1 * dy2 - dy1 * dx2;
		matrix.values[2][1] = det1 / det2;

		matrix.values[0][0] = out_x2 - out_x1 + matrix.values[2][0] * out_x2;
		matrix.values[0][1] = out_x3 - out_x1 + matrix.values[2][1] * out_x3;
		matrix.values[0][2] = out_x1;

		matrix.values[1][0] = out_y2 - out_y1 + matrix.values[2][0] * out_y2;
		matrix.values[1][1] = out_y3 - out_y1 + matrix.values[2][1] * out_y3;
		matrix.values[1][2] = out_y1;
	}

	matrix.values[2][2] = 1.0;

	result->identity();
	result->translate(-in_x1, -in_y1);
	result->scale(scalex, scaley);
	matrix.multiply(result);
}
Esempio n. 2
0
void AffineUnit::calculate_matrix(
	double in_x1,
	double in_y1,
	double in_x2,
	double in_y2,
	double out_x1,
	double out_y1,
	double out_x2,
	double out_y2,
	double out_x3,
	double out_y3,
	double out_x4,
	double out_y4,
	AffineMatrix *result)
{
	AffineMatrix matrix;
	double scalex;
	double scaley;

	scalex = scaley = 1.0;

	if((in_x2 - in_x1) > 0)
      	scalex = 1.0 / (double)(in_x2 - in_x1);

	if((in_y2 - in_y1) > 0)
      	scaley = 1.0 / (double)(in_y2 - in_y1);

/* Determine the perspective transform that maps from
 * the unit cube to the transformed coordinates
 */
    double dx1, dx2, dx3, dy1, dy2, dy3;
    double det1, det2;

    dx1 = out_x2 - out_x4;
    dx2 = out_x3 - out_x4;
    dx3 = out_x1 - out_x2 + out_x4 - out_x3;

    dy1 = out_y2 - out_y4;
    dy2 = out_y3 - out_y4;
    dy3 = out_y1 - out_y2 + out_y4 - out_y3;
// printf("AffineUnit::calculate_matrix %f %f %f %f %f %f\n",
// dx1,
// dx2,
// dx3,
// dy1,
// dy2,
// dy3
// );

/*  Is the mapping affine?  */
    if((dx3 == 0.0) && (dy3 == 0.0))
    {
        matrix.values[0][0] = out_x2 - out_x1;
        matrix.values[0][1] = out_x4 - out_x2;
        matrix.values[0][2] = out_x1;
        matrix.values[1][0] = out_y2 - out_y1;
        matrix.values[1][1] = out_y4 - out_y2;
        matrix.values[1][2] = out_y1;
        matrix.values[2][0] = 0.0;
        matrix.values[2][1] = 0.0;
    }
    else
    {
        det1 = dx3 * dy2 - dy3 * dx2;
        det2 = dx1 * dy2 - dy1 * dx2;
        matrix.values[2][0] = det1 / det2;
        det1 = dx1 * dy3 - dy1 * dx3;
        det2 = dx1 * dy2 - dy1 * dx2;
        matrix.values[2][1] = det1 / det2;

        matrix.values[0][0] = out_x2 - out_x1 + matrix.values[2][0] * out_x2;
        matrix.values[0][1] = out_x3 - out_x1 + matrix.values[2][1] * out_x3;
        matrix.values[0][2] = out_x1;

        matrix.values[1][0] = out_y2 - out_y1 + matrix.values[2][0] * out_y2;
        matrix.values[1][1] = out_y3 - out_y1 + matrix.values[2][1] * out_y3;
        matrix.values[1][2] = out_y1;
    }

    matrix.values[2][2] = 1.0;

// printf("AffineUnit::calculate_matrix 1 %f %f\n", dx3, dy3);
// matrix.dump();

	result->identity();
	result->translate(-in_x1, -in_y1);
	result->scale(scalex, scaley);
	matrix.multiply(result);
// double test[3][3] = { { 0.0896, 0.0, 0.0 },
// 				  { 0.0, 0.0896, 0.0 },
// 				  { -0.00126, 0.0, 1.0 } };
// memcpy(&result->values[0][0], test, sizeof(test));
// printf("AffineUnit::calculate_matrix 4 %p\n", result);
// result->dump();


}