Faster Matrix::setTransformation

This commit is contained in:
vrld
2011-01-02 22:44:19 +01:00
parent ce05194c58
commit 4df411d95a
+15 -6
View File
@@ -118,12 +118,21 @@ namespace love
void Matrix::setTransformation(float x, float y, float angle, float sx, float sy, float ox, float oy)
{
// TODO: This works fine, but should consider speeding this up a little.
setIdentity();
translate(x, y);
rotate(angle);
scale(sx, sy);
translate(-ox, -oy);
memset(e, 0, sizeof(float)*16); // zero out matrix
float c = cos(angle), s = sin(angle);
// matrix multiplication carried out on paper:
// |1 x| |c -s | |sx | |1 -ox|
// | 1 y| |s c | | sy | | 1 -oy|
// | 1 | | 1 | | 1 | | 1 |
// | 1| | 1| | 1| | 1 |
// move rotate scale origin
e[10] = e[15] = 1.0f;
e[0] = sx * c;
e[1] = sx * s;
e[4] = -sy * s;
e[5] = sy * c;
e[12] = -ox * e[0] - oy * e[4] + x;
e[13] = -ox * e[1] - oy * e[5] + y;
}
void Matrix::translate(float x, float y)