/*
Crafter®.Graphics
Copyright (C) 2025 Catcrafts®
Catcrafts.net

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3.0 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
*/

module;

#include <vulkan/vulkan.h>

export module Crafter.Graphics:HeightmapShader;
import std;
import :Camera;
import :VulkanPipeline;
import :DescriptorSet;
import Crafter.Math;

namespace Crafter {
    struct HeightMapData {
        MatrixRowMajor<float, 4, 4, 1> mvp;
        uint32_t stride;
        float spacing;
        uint32_t padding[14];
    };

    export template <typename VertexType>
    class HeightmapShader {
    public:
        MatrixRowMajor<float, 4, 4, 1> transform;
        Camera* camera;
        Buffer<HeightMapData> data;
        Buffer<VertexType> heights;
        std::uint32_t threadCount;
        EventListener<void> cameraUpdate;
        HeightmapShader(uint32_t amount, uint32_t stride, float spacing, Camera* camera) : threadCount(amount), heights(VK_BUFFER_USAGE_STORAGE_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, amount * 4 * 64), data(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT), camera(camera), cameraUpdate(
            &camera->onUpdate, [this](){
                Update();
            }
        ) {
            data.value->stride = stride;
            data.value->spacing = spacing;
            transform = MatrixRowMajor<float, 4, 4, 1>::Identity();
        }
        void WriteDescriptors(VkDescriptorSet set) {
            VkWriteDescriptorSet write[2] = {
                vks::initializers::writeDescriptorSet(set, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &data.descriptor),
                vks::initializers::writeDescriptorSet(set, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1, &heights.descriptor)
            };
            vkUpdateDescriptorSets(VulkanDevice::device, 2, &write[0], 0, nullptr);
        }
        void Update() {
            data.value->mvp = camera->projectionView*transform;
        }
    };
}