Vulcan Nightmare

Experimentally bringing up vulcan support

include/rendering/vk_render_target.hpp

@@ -0,0 +1,71 @@
+#pragma once
+
+#include "rendering/vk_utils.hpp"
+#include <vulkan/vulkan.h>
+#include <vk_mem_alloc.h>
+#include <cstdint>
+
+namespace wowee {
+namespace rendering {
+
+class VkContext;
+
+/**
+ * Off-screen render target encapsulating VkRenderPass + VkFramebuffer + color VkImage.
+ * Used for minimap compositing, world map compositing, and other off-screen passes.
+ */
+class VkRenderTarget {
+public:
+    VkRenderTarget() = default;
+    ~VkRenderTarget();
+
+    VkRenderTarget(const VkRenderTarget&) = delete;
+    VkRenderTarget& operator=(const VkRenderTarget&) = delete;
+
+    /**
+     * Create the render target with given dimensions and format.
+     * Creates: color image, image view, sampler, render pass, framebuffer.
+     */
+    bool create(VkContext& ctx, uint32_t width, uint32_t height,
+                VkFormat format = VK_FORMAT_R8G8B8A8_UNORM);
+
+    /**
+     * Destroy all Vulkan resources.
+     */
+    void destroy(VkDevice device, VmaAllocator allocator);
+
+    /**
+     * Begin the off-screen render pass (clears to given color).
+     * Must be called outside any other active render pass.
+     */
+    void beginPass(VkCommandBuffer cmd,
+                   const VkClearColorValue& clear = {{0.0f, 0.0f, 0.0f, 1.0f}});
+
+    /**
+     * End the off-screen render pass.
+     * After this, the color image is in SHADER_READ_ONLY_OPTIMAL layout.
+     */
+    void endPass(VkCommandBuffer cmd);
+
+    // Accessors
+    VkImageView getColorImageView() const { return colorImage_.imageView; }
+    VkSampler getSampler() const { return sampler_; }
+    VkRenderPass getRenderPass() const { return renderPass_; }
+    VkExtent2D getExtent() const { return { colorImage_.extent.width, colorImage_.extent.height }; }
+    VkFormat getFormat() const { return colorImage_.format; }
+    bool isValid() const { return framebuffer_ != VK_NULL_HANDLE; }
+
+    /**
+     * Descriptor info for binding the color attachment as a texture in a shader.
+     */
+    VkDescriptorImageInfo descriptorInfo() const;
+
+private:
+    AllocatedImage colorImage_{};
+    VkSampler sampler_ = VK_NULL_HANDLE;
+    VkRenderPass renderPass_ = VK_NULL_HANDLE;
+    VkFramebuffer framebuffer_ = VK_NULL_HANDLE;
+};
+
+} // namespace rendering
+} // namespace wowee