#include "pch.h"
#include "canvas_layer.h"

void Layer::Snapshot::create(int w, int h)
{
    for (int i = 0; i < 6; i++)
    {
        image[i] = std::make_unique<uint8_t[]>(w * h * 4);
        std::fill_n(image[i].get(), w * h * 4, 0);
    }
}

void Layer::Snapshot::clear()
{
    for (int i = 0; i < 6; i++)
    {
        m_dirty_face[i] = false;
        m_dirty_box[i] = glm::vec4(0);
        std::fill_n(image[i].get(), width * height * 4, 0);
    }
}

void Layer::Snapshot::optimize()
{
    for (int i = 0; i < 6; i++)
    {
        if (!m_dirty_face[i] || !image[i])
            continue;
        auto data = reinterpret_cast<glm::u8vec4*>(image[i].get());
        glm::ivec2 bbmin(width, height);
        glm::ivec2 bbmax(0);
        for (int y = 0; y < height; y++)
        {
            for (int x = 0; x < width; x++)
            {
                if (data[x + y * width].a > 0)
                {
                    bbmin = glm::min(bbmin, { x, y });
                    bbmax = glm::max(bbmax, { x + 1, y + 1 });
                }
            }
        }
        //glm::vec2 bbsz = bbmax - bbmin;
    }
}