Transform.cpp

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/*
   Copyright 2022 Rishi Challa
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at
 
       http://www.apache.org/licenses/LICENSE-2.0
 
   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/
 
#include "Transform.hpp"
 
#include <Kale/Math/Constants/Constants.hpp>
 
#include <cmath>
 
using namespace Kale;
 
Transform::Transform() : Matrix3f({
    1.0f, 0.0f, 0.0f,
    0.0f, 1.0f, 0.0f,
    0.0f, 0.0f, 1.0f
}) {
    // Empty Body
}
 
Transform::Transform(const Matrix3f& matrix) : Matrix3f(matrix) {
    // Empty Body
}
 
Transform::Transform(Matrix3f&& matrix) : Matrix3f(matrix) {
    // Empty Body
}
 
Transform::Transform(const std::array<float, 9>& arr) : Matrix3f(arr) {
    // Empty Body
}
 
Transform::Transform(std::array<float, 9>&& arr) : Matrix3f(arr) {
    // Empty Body
}
 
Transform::Transform(const Vector2f& translation, float rotation, const Vector2f& scaleFactor, AngleUnit unit) : Matrix3f({
    cos(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleFactor.x, -sin(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleFactor.y, translation.x,
    sin(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleFactor.x, cos(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleFactor.y, translation.y,
    0.0f, 0.0f, 1.0f
}) {
    // Empty Body
}
 
Transform::Transform(float translateX, float translateY, float rotation, float scaleX, float scaleY, AngleUnit unit) : Matrix3f({
    cos(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleX, -sin(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleY, translateX,
    sin(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleX, cos(unit == AngleUnit::Degree ? degToRad(rotation) : rotation) * scaleY, translateY,
    0.0f, 0.0f, 1.0f
}) {
    // Empty Body
}
 
void Transform::setIdentity() {
    data = {
        1.0f, 0.0f, 0.0f,
        0.0f, 1.0f, 0.0f,
        0.0f, 0.0f, 1.0f
    };
}
 
void Transform::scale(const Vector2f& vec) {
    data = Matrix3f::operator*(Matrix3f({
        vec.x, 0.0f, 0.0f,
        0.0f, vec.y, 0.0f,
        0.0f, 0.0f, 1.0f
    })).data;
}
 
void Transform::scale(float x, float y) {
    data = Matrix3f::operator*(Matrix3f({
        x, 0.0f, 0.0f,
        0.0f, y, 0.0f,
        0.0f, 0.0f, 1.0f
    })).data;
}
 
void Transform::scale(float factor) {
    data = Matrix3f::operator*(Matrix3f({
        factor, 0.0f, 0.0f,
        0.0f, factor, 0.0f,
        0.0f, 0.0f, 1.0f
    })).data;
}
 
void Transform::scale(float factor, const Vector2f& origin) {
    translate(origin);
    scale(factor);
    translate(-origin);
}
 
void Transform::scale(float x, float y, const Vector2f& origin) {
    translate(origin);
    scale(x, y);
    translate(-origin);
}
 
void Transform::translate(const Vector2f& vec) {
    data = Matrix3f::operator*(Matrix3f({
        1.0f, 0.0f, vec.x,
        0.0f, 1.0f, vec.y,
        0.0f, 0.0f, 1.0f
    })).data;
}
 
void Transform::translate(float x, float y) {
    data = Matrix3f::operator*(Matrix3f({
        1.0f, 0.0f, x,
        0.0f, 1.0f, y,
        0.0f, 0.0f, 1.0f
    })).data;
}
 
void Transform::rotate(float angle, AngleUnit unit) {
    float c = cos(unit == AngleUnit::Degree ? degToRad(angle) : angle);
    float s = sin(unit == AngleUnit::Degree ? degToRad(angle) : angle);
    data = Matrix3f::operator*(Matrix3f({
        c, -s, 0.0f,
        s, c, 0.0f,
        0.0f, 0.0f, 1.0f
    })).data;
}
 
void Transform::rotate(float angle, AngleUnit unit, const Vector2f& origin) {
    translate(origin);
    rotate(angle, unit);
    translate(-origin);
}
 
void Transform::setTranslation(float x, float y) {
    data[2] = x;
    data[5] = y;
}
 
void Transform::setTranslation(const Vector2f& vec) {
    data[2] = vec.x;
    data[5] = vec.y;
}
 
Vector2f Transform::getTranslation() const {
    return {data[2], data[5]};
}
 
void Transform::setRotation(float angle, AngleUnit unit) {
    if (unit == AngleUnit::Degree) angle = degToRad(angle);
    Vector2f scale = getScale();
    float c = cos(angle);
    float s = sin(angle);
    data[0] = scale.x * c;
    data[1] = scale.y * -s;
    data[3] = scale.x * s;
    data[4] = scale.y * c;
}
 
float Transform::getRotation(AngleUnit unit) const {
    float angle = atan2(data[3], data[4]);
    if (unit == AngleUnit::Degree) angle = radToDeg(angle);
    return angle;
}
 
void Transform::setScale(float scaleX, float scaleY) {
    float c = cos(getRotation(AngleUnit::Radian));
    data[0] = scaleX * c;
    data[4] = scaleY * c;
}
 
void Transform::setScale(float scale) {
    float c = cos(getRotation(AngleUnit::Radian));
    data[0] = scale * c;
    data[4] = scale * c;
}
 
Vector2f Transform::getScale() const {
    return {
        sqrt(data[3] * data[3] + data[4] * data[4]),
        sqrt(data[0] * data[0] + data[1] * data[1])
    };
}
 
Vector2f Transform::transform(const Vector2f& vec) const {
    return {vec.x * data[0] + vec.y * data[1] + data[2], vec.x * data[3] + vec.y * data[4] + data[5]};
}
 
void Transform::transformInplace(Vector2f& vec) const {
    vec.x = vec.x * data[0] + vec.y * data[1] + data[2];
    vec.y = vec.x * data[3] + vec.y * data[4] + data[5];
}
 
Vector2f Transform::inverseTransform(const Vector2f& vec) const {
    float den = data[0] * data[4] - data[1] * data[3];
    return {
        (data[1] * data[5] - data[1] * vec.y - data[2] * data[4] + data[4] * vec.x) / den,
        (-data[0] * data[5] + data[0] * vec.y + data[2] * data[3] - data[3] * vec.x) / den
    };
    // Below system of equations represents transformation where k, j = vec.x, vec.y
    // x * n0 + y * n1 + n2 = k
    // x * n3 + y * n4 + n5 = j
    // Solve the above for x & y ->
    // x = (n1*n5 - n1*j - n2*n4 + n4*k) / (n0*n4 - n1*n3)
    // y = (-n0*n5 + n0*j + n2*n3 - n3*k) / (n0*n4 - n1*n3)
}
 
void Transform::inverseTransformInplace(Vector2f& vec) const {
    float den = data[0] * data[4] - data[1] * data[3];
    vec.x = (data[1] * data[5] - data[1] * vec.y - data[2] * data[4] + data[4] * vec.x) / den;
    vec.y = (-data[0] * data[5] + data[0] * vec.y + data[2] * data[3] - data[3] * vec.x) / den;
}
 
RotatedRect Transform::transform(const RotatedRect& rect) const {
    return {
        transform(rect.point1),
        transform(rect.point2),
        transform(rect.point3),
        transform(rect.point4)
    };
}
 
RotatedRect Transform::inverseTransform(const RotatedRect& rect) const {
    return {
        inverseTransform(rect.point1),
        inverseTransform(rect.point2),
        inverseTransform(rect.point3),
        inverseTransform(rect.point4)
    };
}
 
RotatedRect Transform::transform(const Rect& rect) const {
    return {
        transform(rect.topLeft),
        transform(rect.topRight()),
        transform(rect.bottomRight),
        transform(rect.bottomLeft())
    };
}
 
RotatedRect Transform::inverseTransform(const Rect& rect) const {
    return {
        inverseTransform(rect.topLeft),
        inverseTransform(rect.topRight()),
        inverseTransform(rect.bottomRight),
        inverseTransform(rect.bottomLeft())
    };
}
 
Ray Transform::transform(const Ray& ray) const {
    Ray newRay;
    newRay.origin = transform(ray.origin);
    newRay.direction = transform(ray.direction + ray.origin) - newRay.origin;
    newRay.direction /= newRay.direction.magnitude();
    return newRay;
}
 
Ray Transform::inverseTransform(const Ray& ray) const {
    Ray newRay;
    newRay.origin = inverseTransform(ray.origin);
    newRay.direction = inverseTransform(ray.direction + ray.origin) - newRay.origin;
    newRay.direction /= newRay.direction.magnitude();
    return newRay;
}
 
Line Transform::transform(const Line& line) const {
    return {transform(line.point1), transform(line.point2)};
}
 
Line Transform::inverseTransform(const Line& line) const {
    return {inverseTransform(line.point1), inverseTransform(line.point2)};
}
 
Circle Transform::transform(const Circle& circle) const {
    Circle newCircle;
    newCircle.center = transform(circle.center);
    newCircle.radius = transform({circle.radius, 0.0f}).magnitude();
    return newCircle;
}
 
Circle Transform::inverseTransform(const Circle& circle) const {
    Circle newCircle;
    newCircle.center = inverseTransform(circle.center);
    newCircle.radius = inverseTransform({circle.radius, 0.0f}).magnitude();
    return newCircle;
}