cube-game-plus-plus/client/rendering/renderer/WorldRenderer.cpp

#include "client/rendering/renderer/WorldRenderer.h"

WorldRenderer::WorldRenderer(const World& world) : world(world), texture("resources/textures.png") {
    for(int x = 0; x < World::WORLD_SIZE; x++) {
        for(int y = 0; y < World::WORLD_SIZE; y++) {
            for(int z = 0; z < World::WORLD_SIZE; z++) {
                if(world.getBlock(x, y, z).getId() != 0) {
                    addCube(x, y, z,
                            isAir(x, y - 1, z), isAir(x, y + 1, z),
                            isAir(x - 1, y, z), isAir(x + 1, y, z),
                            isAir(x, y, z + 1), isAir(x, y, z - 1));
                }
            }
        }
    }
    mesh.build();
}

void WorldRenderer::render(float lag, Renderer& renderer) const {
    (void) lag;
    (void) renderer;
    texture.bind(0);
    mesh.draw();
}

bool WorldRenderer::isAir(int x, int y, int z) const {
    return world.getBlock(x, y, z).getId() == 0;
}

void WorldRenderer::addCube(float x, float y, float z, bool bottom, bool top, bool left, bool right, bool front, bool back) {
    Vector3 v000(x, y, z);
    Vector3 v001(x, y, z + 1);
    Vector3 v010(x, y + 1, z);
    Vector3 v011(x, y + 1, z + 1);
    Vector3 v100(x + 1, y, z);
    Vector3 v101(x + 1, y, z + 1);
    Vector3 v110(x + 1, y + 1, z);
    Vector3 v111(x + 1, y + 1, z + 1);

    Vector2 t1(0.1875f, 0.0f);
    Vector2 t2(0.25f, 0.0f);
    Vector2 t3(0.25f, 0.0625f);
    Vector2 t4(0.1875f, 0.0625f);

    if(bottom) {
        Vector2 tb(0.125f, 0.0625f);
        mesh.add(Triangle(Vertex(v000, Vector2(0.125f, 0.0f)), Vertex(v100, t1), Vertex(v001, tb)));
        mesh.add(Triangle(Vertex(v100, t1), Vertex(v101, t4), Vertex(v001, tb)));
    }
    if(top) {
        Vector2 tt(0.3125f, 0.0f);
        mesh.add(Triangle(Vertex(v010, t2), Vertex(v011, t3), Vertex(v110, tt)));
        mesh.add(Triangle(Vertex(v110, tt), Vertex(v011, t3), Vertex(v111, Vector2(0.3125f, 0.0625f))));
    }
    if(left) {
        mesh.add(Triangle(Vertex(v000, t4), Vertex(v001, t3), Vertex(v010, t1)));
        mesh.add(Triangle(Vertex(v001, t3), Vertex(v011, t2), Vertex(v010, t1)));
    }
    if(right) {
        mesh.add(Triangle(Vertex(v100, t3), Vertex(v110, t2), Vertex(v101, t4)));
        mesh.add(Triangle(Vertex(v101, t4), Vertex(v110, t2), Vertex(v111, t1)));
    }
    if(front) {
        mesh.add(Triangle(Vertex(v001, t4), Vertex(v101, t3), Vertex(v011, t1)));
        mesh.add(Triangle(Vertex(v111, t2), Vertex(v011, t1), Vertex(v101, t3)));
    }
    if(back) {
        mesh.add(Triangle(Vertex(v000, t3), Vertex(v010, t2), Vertex(v100, t4)));

        mesh.add(Triangle(Vertex(v110, t1), Vertex(v100, t4), Vertex(v010, t2)));
    }
}