#define NEAR_PLANE (0.01f)

[[vk::binding(0, 1)]]
cbuffer constants {
    float aspect_ratio;
    float fovy_degrees;
    float camera_x;
    float camera_y;
    float camera_distance;
    float camera_tilt;
    int2  drag_start;
    int2  mouse;
    uint  map_width;
};

float4x4 projection(float fovy, float aspect, float near) {
    float g = 1.0 / tan(fovy * 0.5);

    return {
        g / aspect, 0, 0,    0,
                 0, g, 0,    0,
                 0, 0, 0, near,
                 0, 0, 1,    0,
    };
}

float4x4 view(float3 player_pos, float tilt, float camera_distance) {
    float s, c;
    sincos(-tilt, s, c);

    return float4x4(
        1,  0, 0,                      -player_pos.x,
        0,  c, s,                  c * -player_pos.y,
        0, -s, c, s * player_pos.y + camera_distance,
        0,  0, 0,                                  1
    );
}