cudoku/helper.c

#include "helper.h"

Matrix4x4 orthographicProjection2D(float left, float right, float bottom, float top) {
    Matrix4x4 result;

    // Identity matrix
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            result.m[i][j] = 0.0f;
        }
    }

    result.m[0][0] = 2.0f / (right - left);
    result.m[3][0] = -(right + left) / (right - left);
    result.m[1][1] = 2.0f / (top - bottom);
    result.m[3][1] = -(top + bottom) / (top - bottom);
    result.m[2][2] = -1.0f;
    result.m[3][3] = 1.0f;

    return result;
}