//
// Created by Epagris on 2020. 03. 16..
//

#include "Cam.h"
#include "utils.h"

eg3d::Cam::Cam() {

}

void eg3d::Cam::loadDefaults() {
    mProjParams.loadDefaults();
    mViewParams.loadDefaults();
}

const XMFLOAT4X4 &eg3d::Cam::getViewMatrix() const {
    return mMView;
}

const XMFLOAT4X4 &eg3d::Cam::getProjMatrix() const {
    return mMProj;
}

void eg3d::Cam::constructViewMatrix() {
    XMMATRIX r = XMMatrixRotationX(mViewParams.pitch) * XMMatrixRotationY(mViewParams.yaw); // forgatások (yaw, pitch)
    XMMATRIX t = XMMatrixTranslation(mViewParams.position.x, mViewParams.position.y, mViewParams.position.z); // eltolás
    XMStoreFloat4x4(&mMView, MT(t*r)); // view mátrix letárolása

    XMVECTOR dir = XMVectorSet(0.0f, 0.0f, -1.0f, 0.0f); // (0,0,-1) irányba néz alapból a kamera
    XMStoreFloat3(&mVViewDirection, XMVector3Transform(dir, r)); // forgatott vektor kiszámítása és letárolása
}

void eg3d::Cam::constructProjMatrix() {
    XMMATRIX p = XMMatrixPerspectiveFovLH(mProjParams.FOV, mProjParams.AspectRatio, mProjParams.NearPlane, mProjParams.FarPlane);
    XMStoreFloat4x4(&mMProj, MT(p));
}

void eg3d::Cam::setProjParams(const eg3d::ProjParams &pp) {
    mProjParams = pp;
    constructProjMatrix(); // projekciós mátrix újragenerálása
}

eg3d::ProjParams eg3d::Cam::getProjParams() const {
    return mProjParams;
}

void eg3d::Cam::setViewParams(const eg3d::ViewParams &vp) {
    mViewParams = vp;
    constructViewMatrix();
}

eg3d::ViewParams eg3d::Cam::getViewParams() const {
    return mViewParams;
}

void eg3d::Cam::advance(float ds) {
    XMVECTOR s = XMLoadFloat3(&mViewParams.position);
    XMVECTOR dir = XMLoadFloat3(&mVViewDirection);
    s = XMVectorAdd(s, XMVectorScale(dir, ds));
    XMStoreFloat3(&mViewParams.position, s);

    constructViewMatrix();
}

void eg3d::Cam::yaw(float dphi) {
    mViewParams.yaw += dphi;
    constructViewMatrix();
}

void eg3d::Cam::pitch(float drho) {
    mViewParams.pitch += drho;
    constructViewMatrix();
}

// -----------------------------

eg3d::ProjParams::ProjParams() {
    loadDefaults();
}

void eg3d::ProjParams::loadDefaults() {
    FOV = XM_PIDIV2; // 90 fokos látószög
    AspectRatio = 1.0f; // 1:1-es képarány
    NearPlane = 1.0f; // közeli sík
    FarPlane = 10.0f;
}

eg3d::ViewParams::ViewParams() {}

void eg3d::ViewParams::loadDefaults() {
    position.x = position.y = position.z = 0.0f; // (0,0,0), origó
    yaw = 0.0f; // nincs forgatás
    pitch = 0.0f; // nincs billentés
}