◆ render_empty_window()

void MayaFlux::Core::BackendWindowHandler::render_empty_window ( WindowRenderContext & ctx )
private
Render empty windows with clear color.
Parameters
ctx	Window render context
For windows that are registered for processing but have no buffers attached, this performs a minimal clear pass so the window is visible and responsive to input events.
Definition at line 807 of file BackendWindowHandler.cpp.
{
    auto window = ctx.window;
 
    if (!window || !window->get_state().is_visible || !window->get_rendering_buffers().empty()) {
        return;
    }
 
    try {
        auto device = m_context.get_device();
 
        size_t frame_index = ctx.current_frame;
        auto& in_flight = ctx.in_flight[frame_index];
        auto& image_available = ctx.image_available[frame_index];
        auto& render_finished = ctx.render_finished[frame_index];
 
        auto cmd_buffer = ctx.clear_command_buffers[frame_index];
        if (!cmd_buffer) {
            MF_RT_ERROR(Journal::Component::Core, Journal::Context::GraphicsCallback,
                "Clear command buffer not allocated for window '{}'",
                window->get_create_info().title);
            return;
        }
 
        if (device.waitForFences(1, &in_flight, VK_TRUE, UINT64_MAX) == vk::Result::eTimeout) {
            return;
        }
        cmd_buffer.reset({});
 
        auto image_index_opt = ctx.swapchain->acquire_next_image(image_available);
        if (!image_index_opt.has_value()) {
            ctx.needs_recreation = true;
            return;
        }
        ctx.current_image_index = image_index_opt.value();
 
        if (device.resetFences(1, &in_flight) != vk::Result::eSuccess) {
            return;
        }
 
        vk::CommandBufferBeginInfo begin_info {};
        begin_info.flags = vk::CommandBufferUsageFlagBits::eOneTimeSubmit;
        cmd_buffer.begin(begin_info);
 
        const auto& image_views = ctx.swapchain->get_image_views();
        auto extent = ctx.swapchain->get_extent();
 
        vk::RenderingAttachmentInfo color_attachment {};
        color_attachment.imageView = image_views[ctx.current_image_index];
        color_attachment.imageLayout = vk::ImageLayout::eColorAttachmentOptimal;
        color_attachment.loadOp = vk::AttachmentLoadOp::eClear;
        color_attachment.storeOp = vk::AttachmentStoreOp::eStore;
        color_attachment.clearValue.color = vk::ClearColorValue(
            window->get_create_info().clear_color);
 
        vk::RenderingInfo rendering_info {};
        rendering_info.renderArea = vk::Rect2D { { 0, 0 }, extent };
        rendering_info.layerCount = 1;
        rendering_info.colorAttachmentCount = 1;
        rendering_info.pColorAttachments = &color_attachment;
 
        vk::ImageMemoryBarrier barrier {};
        barrier.oldLayout = vk::ImageLayout::eUndefined;
        barrier.newLayout = vk::ImageLayout::eColorAttachmentOptimal;
        barrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        barrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        barrier.image = ctx.swapchain->get_images()[ctx.current_image_index];
        barrier.subresourceRange.aspectMask = vk::ImageAspectFlagBits::eColor;
        barrier.subresourceRange.levelCount = 1;
        barrier.subresourceRange.layerCount = 1;
        barrier.srcAccessMask = {};
        barrier.dstAccessMask = vk::AccessFlagBits::eColorAttachmentWrite;
 
        cmd_buffer.pipelineBarrier(
            vk::PipelineStageFlagBits::eTopOfPipe,
            vk::PipelineStageFlagBits::eColorAttachmentOutput,
            {}, {}, {}, barrier);
 
        cmd_buffer.beginRendering(rendering_info);
        cmd_buffer.endRendering();
 
        barrier.oldLayout = vk::ImageLayout::eColorAttachmentOptimal;
        barrier.newLayout = vk::ImageLayout::ePresentSrcKHR;
        barrier.srcAccessMask = vk::AccessFlagBits::eColorAttachmentWrite;
        barrier.dstAccessMask = {};
 
        cmd_buffer.pipelineBarrier(
            vk::PipelineStageFlagBits::eColorAttachmentOutput,
            vk::PipelineStageFlagBits::eBottomOfPipe,
            {}, {}, {}, barrier);
 
        cmd_buffer.end();
 
        submit_and_present(window, cmd_buffer);
 
        ctx.current_frame = (ctx.current_frame + 1) % ctx.in_flight.size();
 
    } catch (const std::exception& e) {
        MF_RT_ERROR(Journal::Component::Core, Journal::Context::GraphicsCallback,
            "Failed to render empty window '{}': {}",
            window->get_create_info().title, e.what());
    }
}