#include <iostream>

#include "sre/SDLRenderer.hpp"

#include "sre/SpriteAtlas.hpp"

#include "sre/Texture.hpp"

#include "sre/Material.hpp"

#include "sre/Inspector.hpp"

#include "glm/gtc/random.hpp"

#define GLM_ENABLE_EXPERIMENTAL

#include "glm/gtx/transform.hpp"

#include "glm/ext.hpp"

// lua headers

#include "sol.hpp"

using namespace sre;

using namespace std;

using namespace sol;

// Captures debug information from Box2D as lines (polygon fill and color is discarded)

class ScriptableSphereObject {

private:

std::shared_ptr<Mesh> mesh;

std::shared_ptr<Material> material;

public:

int x;

int z;

float pos_x;

float pos_y;

float pos_z;

string objectName;

ScriptableSphereObject(std::shared_ptr<Mesh> mesh,std::shared_ptr<Material> material, int x, int z)

:mesh(mesh), material(material), x(x), z(z)

{

pos_x = x;

pos_y = 0;

pos_z = z;

objectName = string("o")+to_string(x)+"_"+to_string(z);

}

void draw(RenderPass& renderPass){

renderPass.draw(mesh, glm::translate(glm::vec3{pos_x,pos_y,pos_z}), material);

}

};

class LuaExample {

public:

LuaExample()

{

r.init();

r.setWindowTitle("Lua example");

l.addLight(Light::create().withDirectionalLight({1,1,1}).withColor({1,1,1}).build());

auto mat = Shader::getStandardPhong()->createMaterial();

mat->setColor({1,0,0,1});

auto sphere = Mesh::create().withSphere().build();

lua.open_libraries(sol::lib::base, sol::lib::package, sol::lib::math);

// callback set title

lua.set_function("setTitle", [&](sol::this_state, sol::variadic_args va){

string s = va[0];

r.setWindowTitle(s);

});

updateLuaScript();

// create objects

for (int x = -5;x<=5;x++){

for (int y = -5;y<=5;y++) {

objects.emplace_back(sphere, mat, x, y);

}

}

camera.setPerspectiveProjection(45,0.1,100);

camera.lookAt({0,15,-20},{0,0,0},{0,1,0});

r.frameUpdate = [&](float deltaTime){

update(deltaTime);

};

r.frameRender = [&](){

render();

};

r.startEventLoop();

}

void updateLuaScript() {

lua.script(luaScript); // evaluate lua script

sol::function fn = lua["updatepos"]; // get lua function update pos

updatepos = fn; // get C++ functional reference to lua script

}

void update(float deltaTime){

static float totalTime = 0;

totalTime += deltaTime;

for (auto & o : objects){

o.pos_y = (float)updatepos(o.x,o.z,totalTime);

}

}

void render(){

RenderPass rp = RenderPass::create()

.withCamera(camera)

.withWorldLights(&l)

.build();

for (auto & o : objects){

o.draw(rp);

}

ImGui::InputTextMultiline("Lua script", luaScript , 2048);

if (ImGui::Button("Update")){

updateLuaScript();

}

}

private:

static const int luaScriptSize = 2048;

char luaScript[luaScriptSize] =

"-- Function evaluated for each pos\n"

"function updatepos (x, z, time) \n"

" return math.sin(x + z*9 + time) \n"

"end\n"

"-- Remove '--' to see callback\n"

"-- setTitle('callback to setTitle')";

std::vector<ScriptableSphereObject> objects;

SDLRenderer r;

WorldLights l;

Camera camera;

sol::state lua;

std::function<double(int, int, double)> updatepos;

};

int main() {

std::cout << "https://github.com/mortennobel/SimpleRenderEngineProject" << std::endl;

new LuaExample();

return 0;

}