/*!
 * \file src/RoomMesh.cpp
 * \brief World Room Mesh
 *
 * \author xythobuz
 */

#include "global.h"
#include "Mesh.h"
#include "TextureManager.h"
#include "system/Window.h"
#include "RoomMesh.h"

RoomMesh::RoomMesh(const std::vector<RoomVertexTR2>& vert,
                   const std::vector<IndexedRectangle>& rect,
                   const std::vector<IndexedRectangle>& tri) {
    for (auto& t : rect) {
        indices.push_back(0);
        vertices.push_back(glm::vec3(vert.at(t.v1).x, vert.at(t.v1).y, vert.at(t.v1).z));
        vertices.push_back(glm::vec3(vert.at(t.v2).x, vert.at(t.v2).y, vert.at(t.v2).z));
        vertices.push_back(glm::vec3(vert.at(t.v3).x, vert.at(t.v3).y, vert.at(t.v3).z));
        vertices.push_back(glm::vec3(vert.at(t.v4).x, vert.at(t.v4).y, vert.at(t.v4).z));
        textures.push_back(t.texture);
    }

    for (auto& t : tri) {
        indices.push_back(1);
        vertices.push_back(glm::vec3(vert.at(t.v1).x, vert.at(t.v1).y, vert.at(t.v1).z));
        vertices.push_back(glm::vec3(vert.at(t.v2).x, vert.at(t.v2).y, vert.at(t.v2).z));
        vertices.push_back(glm::vec3(vert.at(t.v3).x, vert.at(t.v3).y, vert.at(t.v3).z));
        textures.push_back(t.texture);
    }
}

void RoomMesh::prepare() {
    std::vector<unsigned short> ind;
    std::vector<glm::vec3> vert;
    std::vector<unsigned int> tex;

    std::map<PackedVertex, unsigned short> vertexMap;

    int vertIndex = 0;
    for (int i = 0; i < indices.size(); i++) {
        unsigned int texture = getTextureManager().getTile(textures.at(i)).getTexture();
        for (int v = 0; v < ((indices.at(i) == 0) ? 4 : 3); v++) {
            glm::vec2 uv = getTextureManager().getTile(textures.at(i)).getUV(v);
            PackedVertex p(vertices.at(vertIndex + v), uv, texture);
            unsigned short s;
            if (findSimilarVertex(p, vertexMap, s)) {
                ind.push_back(s); // Vertex already cached
            } else {
                vertexMap[p] = vert.size();
                ind.push_back(vert.size());
                vert.push_back(p.pos);
                uvs.push_back(p.uv);
                tex.push_back(p.tex);
            }
        }

        if (indices.at(i) == 0) {
            ind.push_back(ind.at(ind.size() - 2));
            ind.push_back(ind.at(ind.size() - 5));
        }

        vertIndex += (indices.at(i) == 0) ? 4 : 3;
    }

    assert((ind.size() % 3) == 0);

    indices = std::move(ind);
    vertices = std::move(vert);
    textures = std::move(tex);
}

void RoomMesh::display(glm::mat4 MVP) {
    if (indices.size() > 0) {
        unsigned int indexStart = 0;
        unsigned int indexPos = 1;
        unsigned int texture = textures.at(indices.at(0));

        while ((indexStart != indexPos) && (indexPos < indices.size())) {
            while ((indexPos < indices.size()) && (textures.at(indices.at(indexPos)) == texture))
                indexPos++;

            std::vector<unsigned short> ind(indices.begin() + indexStart, indices.begin() + indexPos);
            Window::drawGL(vertices, uvs, ind, MVP, texture);

            if (indexPos < indices.size()) {
                indexStart = indexPos;
                indexPos += 1;
                texture = textures.at(indices.at(indexStart));
            }
        }
    }
}