Add the renderer process

The renderer becomes two programs: the adapter (t5deRenderEngine.dll, 32-bit, in IMVU's process) and a 64-bit renderer process (t5de-renderer.exe) drawing with Diligent Engine, fetched with FetchContent and pinned. For now a spike: the adapter starts the renderer process for each engine and signals each frame through a shared memory channel, and the renderer process draws a box into a child window in the client's 3D view.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

adapter/passthrough_engine.hpp

@@ -0,0 +1,76 @@
+#pragma once
+// A renderer that forwards every call to another one (IMVU's Direct3D engine) and logs what a frame is made of: proof
+// that our declaration of the interface matches IMVU's, and a way to see how the client draws.
+
+#include <array>
+#include <cstdint>
+#include <memory>
+
+#include "renderer_process.hpp"
+#include "t5de/imvu/render_engine.hpp"
+
+namespace t5de {
+
+class PassthroughEngine final : public imvu::PiRenderEngine {
+public:
+    // renderer may be null.
+    PassthroughEngine(imvu::SharedPtr<imvu::PiRenderEngine> inner, std::unique_ptr<RendererProcess> renderer);
+    ~PassthroughEngine() override;
+
+    void resizeFrameBuffer(imvu::Vec2i size) override;
+    void enable2dFrameBuffer() override;
+    void clear(std::uint32_t flags, imvu::Color color) override;
+    void setProjection(imvu::Vec2i viewport, const imvu::Mat4f& projection) override;
+    void setModelSpace(const imvu::Transform& model) override;
+    void setViewSpace(const imvu::Transform& view) override;
+    void setTextures(imvu::PiRenderTexture* texture0, imvu::PiRenderTexture* texture1) override;
+    void setDepthTestingOn(bool on) override;
+    void setDepthWritingOn(bool on) override;
+    void setBlendMode(imvu::RenderBlendMode mode) override;
+    void setAlphaTestingOn(bool on) override;
+    void setAlphaTestValue(float value) override;
+    void setBlendingOn(bool on) override;
+    void setBackFaceCullingOn(bool on) override;
+    void setNormalInvertingOn(bool on) override;
+    void setLightingOn(bool on) override;
+    void setLightProperties(std::uint32_t index, const imvu::LightProperties& light) override;
+    void setFogOn(bool on) override;
+    void setFogAttributes(float start, float end, imvu::Color color) override;
+    void setTextureTransformMatrixIdentity(std::uint32_t stage) override;
+    void setTextureTransformMatrix(std::uint32_t stage, const imvu::TextureTransform& transform) override;
+    void setEnvironmentAmbient(imvu::Color color) override;
+    imvu::PiRenderTexture* newRenderTexture(const imvu::Pixmap& pixmap, std::uint32_t flags) override;
+    imvu::PiInternalIndexBuffer* newIndexBuffer(std::uint32_t count, const std::uint16_t* indices) override;
+    imvu::PiInternalVertexBuffer* newStaticVertexBuffer(const void* data, std::uint32_t stride,
+                                                        std::uint32_t elementSize,
+                                                        std::uint32_t elementCount) override;
+    imvu::PiInternalVertexBuffer* newDynamicVertexBuffer(std::uint32_t elementSize,
+                                                         std::uint32_t elementCount) override;
+    imvu::SharedPtr<imvu::PiPixmapRenderTarget> newPixmapRenderTarget(imvu::Vec2i size) override;
+    imvu::SharedPtr<imvu::PiTextureRenderTarget> newTextureRenderTarget(imvu::Vec2i size) override;
+    void beginRendering(imvu::PiRenderTarget* target) override;
+    void endRendering() override;
+    void drawTriangles(imvu::PiInternalIndexBuffer* indices, imvu::PiInternalVertexBuffer* positions,
+                       imvu::PiInternalVertexBuffer* normals, imvu::PiInternalVertexBuffer* texCoords,
+                       imvu::PiInternalVertexBuffer* colors) override;
+    void drawLine(imvu::Vec3f from, imvu::Vec3f to, std::uint32_t color) override;
+    void drawPointSprites(const imvu::PointSpriteVector& sprites) override;
+    void drawTrianglesFromMemory(std::uint32_t vertexCount, std::uint32_t indexCount, const std::uint16_t* indices,
+                                 const imvu::VertexAttributeArray<imvu::Vec3f>& positions,
+                                 const imvu::VertexAttributeArray<imvu::Vec3f>& normals,
+                                 const imvu::VertexAttributeArray<imvu::Vec2f>& texCoords,
+                                 const imvu::VertexAttributeArray<imvu::Color>& colors) override;
+
+    // The interface's methods, by vtable slot (slot 0, the destructor, isn't counted).
+    static constexpr std::size_t slots = 35;
+
+private:
+    void count(std::size_t slot);
+
+    imvu::SharedPtr<imvu::PiRenderEngine> inner_;
+    std::unique_ptr<RendererProcess> renderer_;
+    std::array<std::uint32_t, slots> calls_{};
+    std::uint64_t frames_ = 0;
+};
+
+} // namespace t5de