pigine/math/Matrix.cpp

#include <cmath>
#include <iomanip>
#include <cstring>

#include "math/Matrix.h"

Matrix::Matrix() {
    setToIdentity();
}

Matrix& Matrix::set(const Matrix& other) {
    *this = other;
    return *this;
}

Matrix& Matrix::setToIdentity() {
    data[0] = 1.0f;
    data[1] = 0.0f;
    data[2] = 0.0f;
    data[3] = 0.0f;
    data[4] = 1.0f;
    data[5] = 0.0f;
    data[6] = 0.0f;
    data[7] = 0.0f;
    data[8] = 1.0f;
    return *this;
}

Matrix& Matrix::set(uint index, float f) {
    data[index] = f;
    return *this;
}

const float* Matrix::getValues() const {
    return data;
}

Matrix& Matrix::mul(const Matrix& m) {
    float mNew[9];
    mNew[0] = data[0] * m.data[0] + data[3] * m.data[1] + data[6] * m.data[2];
    mNew[1] = data[1] * m.data[0] + data[4] * m.data[1] + data[7] * m.data[2];
    mNew[2] = data[2] * m.data[0] + data[5] * m.data[1] + data[8] * m.data[2];
    mNew[3] = data[0] * m.data[3] + data[3] * m.data[4] + data[6] * m.data[5];
    mNew[4] = data[1] * m.data[3] + data[4] * m.data[4] + data[7] * m.data[5];
    mNew[5] = data[2] * m.data[3] + data[5] * m.data[4] + data[8] * m.data[5];
    mNew[6] = data[0] * m.data[6] + data[3] * m.data[7] + data[6] * m.data[8];
    mNew[7] = data[1] * m.data[6] + data[4] * m.data[7] + data[7] * m.data[8];
    mNew[8] = data[2] * m.data[6] + data[5] * m.data[7] + data[8] * m.data[8];
    memcpy(data, mNew, sizeof (float) * 9);
    return *this;
}

Matrix& Matrix::scale(float sx, float sy) {
    data[0] *= sx;
    data[1] *= sx;
    data[2] *= sx;
    data[3] *= sy;
    data[4] *= sy;
    data[5] *= sy;
    return *this;
}

Matrix& Matrix::scale(float s) {
    return scale(s, s);
}

Matrix& Matrix::translate(float tx, float ty) {
    return translateX(tx).translateY(ty);
}

Matrix& Matrix::translateX(float tx) {
    data[6] += data[0] * tx;
    data[7] += data[1] * tx;
    data[8] += data[2] * tx;
    return *this;
}

Matrix& Matrix::translateY(float ty) {
    data[6] += data[3] * ty;
    data[7] += data[4] * ty;
    data[8] += data[5] * ty;
    return *this;
}

Matrix& Matrix::translateTo(float tx, float ty) {
    data[0] = 1.0f;
    data[1] = 0.0f;
    data[2] = 0.0f;
    data[3] = 0.0f;
    data[4] = 1.0f;
    data[5] = 0.0f;
    data[6] = tx;
    data[7] = ty;
    data[8] = 1.0f;
    return *this;
}

Matrix& Matrix::rotate(float degrees) {
    degrees *= M_PIf32 / 180.0f;
    float sin;
    float cos;
    sincosf(degrees, &sin, &cos);
     
    float a = data[0];
    float b = data[3];
    data[0] = a * cos + b * sin;
    data[3] = b * cos - a * sin;
    
    a = data[1];
    b = data[4];
    data[1] = a * cos + b * sin;
    data[4] = b * cos - a * sin;
    
    a = data[2];
    b = data[5];
    data[2] = a * cos + b * sin;
    data[5] = b * cos - a * sin;
    return *this;
}

std::ostream& operator<<(std::ostream& os, const Matrix& m) {
    const float* data = m.getValues();
    os << "Matrix\n(\n";
    os << std::fixed << std::setprecision(5);
    for(int i = 0; i < 3; i++) {
        os << std::setw(15);
        os << data[i] << ", ";
        os << std::setw(15);
        os << data[i + 3] << ", ";
        os << std::setw(15);
        os << data[i + 6] << "\n";
    }
    os << std::defaultfloat;
    os << ")";
    return os;
}