Kelsidavis-WoWee/src/rendering/clouds.cpp

#include "rendering/clouds.hpp"
#include "rendering/vk_context.hpp"
#include "rendering/vk_shader.hpp"
#include "rendering/vk_pipeline.hpp"
#include "rendering/vk_frame_data.hpp"
#include "rendering/vk_utils.hpp"
#include "core/logger.hpp"
#include <glm/gtc/matrix_transform.hpp>
#include <cmath>

namespace wowee {
namespace rendering {

Clouds::Clouds() = default;

Clouds::~Clouds() {
    shutdown();
}

bool Clouds::initialize(VkContext* ctx, VkDescriptorSetLayout perFrameLayout) {
    LOG_INFO("Initializing cloud system (Vulkan)");

    vkCtx_ = ctx;
    VkDevice device = vkCtx_->getDevice();

    // ------------------------------------------------------------------ shaders
    VkShaderModule vertModule;
    if (!vertModule.loadFromFile(device, "assets/shaders/clouds.vert.spv")) {
        LOG_ERROR("Failed to load clouds vertex shader");
        return false;
    }

    VkShaderModule fragModule;
    if (!fragModule.loadFromFile(device, "assets/shaders/clouds.frag.spv")) {
        LOG_ERROR("Failed to load clouds fragment shader");
        return false;
    }

    VkPipelineShaderStageCreateInfo vertStage = vertModule.stageInfo(VK_SHADER_STAGE_VERTEX_BIT);
    VkPipelineShaderStageCreateInfo fragStage = fragModule.stageInfo(VK_SHADER_STAGE_FRAGMENT_BIT);

    // ------------------------------------------------------------------ push constants
    // Fragment-only push: vec4 cloudColor + float density + float windOffset = 24 bytes
    VkPushConstantRange pushRange{};
    pushRange.stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
    pushRange.offset     = 0;
    pushRange.size       = sizeof(CloudPush); // 24 bytes

    // ------------------------------------------------------------------ pipeline layout
    pipelineLayout_ = createPipelineLayout(device, {perFrameLayout}, {pushRange});
    if (pipelineLayout_ == VK_NULL_HANDLE) {
        LOG_ERROR("Failed to create clouds pipeline layout");
        return false;
    }

    // ------------------------------------------------------------------ vertex input
    // Vertex: vec3 pos only, stride = 12 bytes
    VkVertexInputBindingDescription binding{};
    binding.binding   = 0;
    binding.stride    = sizeof(glm::vec3); // 12 bytes
    binding.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

    VkVertexInputAttributeDescription posAttr{};
    posAttr.location = 0;
    posAttr.binding  = 0;
    posAttr.format   = VK_FORMAT_R32G32B32_SFLOAT;
    posAttr.offset   = 0;

    std::vector<VkDynamicState> dynamicStates = {
        VK_DYNAMIC_STATE_VIEWPORT,
        VK_DYNAMIC_STATE_SCISSOR
    };

    // ------------------------------------------------------------------ pipeline
    pipeline_ = PipelineBuilder()
        .setShaders(vertStage, fragStage)
        .setVertexInput({binding}, {posAttr})
        .setTopology(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST)
        .setRasterization(VK_POLYGON_MODE_FILL, VK_CULL_MODE_NONE)
        .setDepthTest(true, false, VK_COMPARE_OP_LESS_OR_EQUAL) // test on, write off (sky layer)
        .setColorBlendAttachment(PipelineBuilder::blendAlpha())
        .setLayout(pipelineLayout_)
        .setRenderPass(vkCtx_->getImGuiRenderPass())
        .setDynamicStates(dynamicStates)
        .build(device);

    vertModule.destroy();
    fragModule.destroy();

    if (pipeline_ == VK_NULL_HANDLE) {
        LOG_ERROR("Failed to create clouds pipeline");
        return false;
    }

    // ------------------------------------------------------------------ geometry
    generateMesh();
    createBuffers();

    LOG_INFO("Cloud system initialized: ", indexCount_ / 3, " triangles");
    return true;
}

void Clouds::shutdown() {
    destroyBuffers();

    if (vkCtx_) {
        VkDevice device = vkCtx_->getDevice();
        if (pipeline_ != VK_NULL_HANDLE) {
            vkDestroyPipeline(device, pipeline_, nullptr);
            pipeline_ = VK_NULL_HANDLE;
        }
        if (pipelineLayout_ != VK_NULL_HANDLE) {
            vkDestroyPipelineLayout(device, pipelineLayout_, nullptr);
            pipelineLayout_ = VK_NULL_HANDLE;
        }
    }

    vkCtx_ = nullptr;
}

// ---------------------------------------------------------------------------
// Render
// ---------------------------------------------------------------------------

void Clouds::render(VkCommandBuffer cmd, VkDescriptorSet perFrameSet, float timeOfDay) {
    if (!enabled_ || pipeline_ == VK_NULL_HANDLE) {
        return;
    }

    glm::vec3 color = getCloudColor(timeOfDay);

    CloudPush push{};
    push.cloudColor  = glm::vec4(color, 1.0f);
    push.density     = density_;
    push.windOffset  = windOffset_;

    vkCmdBindPipeline(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline_);

    // Bind per-frame UBO (set 0 — vertex shader reads view/projection from here)
    vkCmdBindDescriptorSets(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout_,
        0, 1, &perFrameSet, 0, nullptr);

    // Push cloud params to fragment shader
    vkCmdPushConstants(cmd, pipelineLayout_,
        VK_SHADER_STAGE_FRAGMENT_BIT,
        0, sizeof(push), &push);

    VkDeviceSize offset = 0;
    vkCmdBindVertexBuffers(cmd, 0, 1, &vertexBuffer_, &offset);
    vkCmdBindIndexBuffer(cmd, indexBuffer_, 0, VK_INDEX_TYPE_UINT32);

    vkCmdDrawIndexed(cmd, static_cast<uint32_t>(indexCount_), 1, 0, 0, 0);
}

// ---------------------------------------------------------------------------
// Update
// ---------------------------------------------------------------------------

void Clouds::update(float deltaTime) {
    if (!enabled_) {
        return;
    }
    windOffset_ += deltaTime * windSpeed_ * 0.05f; // Slow drift
}

// ---------------------------------------------------------------------------
// Cloud colour (unchanged logic from GL version)
// ---------------------------------------------------------------------------

glm::vec3 Clouds::getCloudColor(float timeOfDay) const {
    glm::vec3 dayColor(0.95f, 0.95f, 1.0f);

    if (timeOfDay >= 5.0f && timeOfDay < 7.0f) {
        // Dawn — orange tint fading to day
        float t = (timeOfDay - 5.0f) / 2.0f;
        return glm::mix(glm::vec3(1.0f, 0.7f, 0.5f), dayColor, t);
    } else if (timeOfDay >= 17.0f && timeOfDay < 19.0f) {
        // Dusk — day fading to orange/pink
        float t = (timeOfDay - 17.0f) / 2.0f;
        return glm::mix(dayColor, glm::vec3(1.0f, 0.6f, 0.4f), t);
    } else if (timeOfDay >= 20.0f || timeOfDay < 5.0f) {
        // Night — dark blue-grey
        return glm::vec3(0.15f, 0.15f, 0.25f);
    }

    return dayColor;
}

// ---------------------------------------------------------------------------
// Density setter
// ---------------------------------------------------------------------------

void Clouds::setDensity(float density) {
    density_ = glm::clamp(density, 0.0f, 1.0f);
}

// ---------------------------------------------------------------------------
// Mesh generation — identical algorithm to GL version
// ---------------------------------------------------------------------------

void Clouds::generateMesh() {
    vertices_.clear();
    indices_.clear();

    // Upper hemisphere
    for (int ring = 0; ring <= RINGS; ++ring) {
        float phi        = (ring / static_cast<float>(RINGS)) * (static_cast<float>(M_PI) * 0.5f);
        float y          = RADIUS * std::cos(phi);
        float ringRadius = RADIUS * std::sin(phi);

        for (int seg = 0; seg <= SEGMENTS; ++seg) {
            float theta = (seg / static_cast<float>(SEGMENTS)) * (2.0f * static_cast<float>(M_PI));
            float x = ringRadius * std::cos(theta);
            float z = ringRadius * std::sin(theta);
            vertices_.push_back(glm::vec3(x, y, z));
        }
    }

    for (int ring = 0; ring < RINGS; ++ring) {
        for (int seg = 0; seg < SEGMENTS; ++seg) {
            uint32_t current = static_cast<uint32_t>(ring * (SEGMENTS + 1) + seg);
            uint32_t next    = current + static_cast<uint32_t>(SEGMENTS + 1);

            indices_.push_back(current);
            indices_.push_back(next);
            indices_.push_back(current + 1);

            indices_.push_back(current + 1);
            indices_.push_back(next);
            indices_.push_back(next + 1);
        }
    }

    indexCount_ = static_cast<int>(indices_.size());
}

// ---------------------------------------------------------------------------
// GPU buffer management
// ---------------------------------------------------------------------------

void Clouds::createBuffers() {
    AllocatedBuffer vbuf = uploadBuffer(*vkCtx_,
        vertices_.data(),
        vertices_.size() * sizeof(glm::vec3),
        VK_BUFFER_USAGE_VERTEX_BUFFER_BIT);
    vertexBuffer_ = vbuf.buffer;
    vertexAlloc_  = vbuf.allocation;

    AllocatedBuffer ibuf = uploadBuffer(*vkCtx_,
        indices_.data(),
        indices_.size() * sizeof(uint32_t),
        VK_BUFFER_USAGE_INDEX_BUFFER_BIT);
    indexBuffer_ = ibuf.buffer;
    indexAlloc_  = ibuf.allocation;

    // CPU data no longer needed
    vertices_.clear();
    vertices_.shrink_to_fit();
    indices_.clear();
    indices_.shrink_to_fit();
}

void Clouds::destroyBuffers() {
    if (!vkCtx_) return;

    VmaAllocator allocator = vkCtx_->getAllocator();

    if (vertexBuffer_ != VK_NULL_HANDLE) {
        vmaDestroyBuffer(allocator, vertexBuffer_, vertexAlloc_);
        vertexBuffer_ = VK_NULL_HANDLE;
        vertexAlloc_  = VK_NULL_HANDLE;
    }
    if (indexBuffer_ != VK_NULL_HANDLE) {
        vmaDestroyBuffer(allocator, indexBuffer_, indexAlloc_);
        indexBuffer_ = VK_NULL_HANDLE;
        indexAlloc_  = VK_NULL_HANDLE;
    }
}

} // namespace rendering
} // namespace wowee