void Matrix4::mapRect(Rect& r) const {
if (isIdentity()) return;
if (isSimple()) {
MUL_ADD_STORE(r.left, data[kScaleX], data[kTranslateX]);
MUL_ADD_STORE(r.right, data[kScaleX], data[kTranslateX]);
MUL_ADD_STORE(r.top, data[kScaleY], data[kTranslateY]);
MUL_ADD_STORE(r.bottom, data[kScaleY], data[kTranslateY]);
if (r.left > r.right) {
float x = r.left;
r.left = r.right;
r.right = x;
}
if (r.top > r.bottom) {
float y = r.top;
r.top = r.bottom;
r.bottom = y;
}
return;
}
float vertices[] = {
r.left, r.top,
r.right, r.top,
r.right, r.bottom,
r.left, r.bottom
};
float x, y, z;
for (int i = 0; i < 8; i+= 2) {
float px = vertices[i];
float py = vertices[i + 1];
x = px * data[kScaleX] + py * data[kSkewX] + data[kTranslateX];
y = px * data[kSkewY] + py * data[kScaleY] + data[kTranslateY];
z = px * data[kPerspective0] + py * data[kPerspective1] + data[kPerspective2];
if (z) z = 1.0f / z;
vertices[i] = x * z;
vertices[i + 1] = y * z;
}
r.left = r.right = vertices[0];
r.top = r.bottom = vertices[1];
for (int i = 2; i < 8; i += 2) {
x = vertices[i];
y = vertices[i + 1];
if (x < r.left) r.left = x;
else if (x > r.right) r.right = x;
if (y < r.top) r.top = y;
else if (y > r.bottom) r.bottom = y;
}
}
void Matrix4::mapPoint(float& x, float& y) const {
if (isSimple()) {
MUL_ADD_STORE(x, data[kScaleX], data[kTranslateX]);
MUL_ADD_STORE(y, data[kScaleY], data[kTranslateY]);
return;
}
float dx = x * data[kScaleX] + y * data[kSkewX] + data[kTranslateX];
float dy = x * data[kSkewY] + y * data[kScaleY] + data[kTranslateY];
float dz = x * data[kPerspective0] + y * data[kPerspective1] + data[kPerspective2];
if (dz) dz = 1.0f / dz;
x = dx * dz;
y = dy * dz;
}
