[fix]: generalize render targets and window seams

1 files changed, 26 insertions, 6 deletions

diff --git a/src/rendering/rhi.h b/src/rendering/rhi.h
index 65f10b5..2110926 100644
--- a/src/rendering/rhi.h
+++ b/src/rendering/rhi.h
@@ -18,11 +18,33 @@ namespace Donut::RHI
 {
     enum class Format
     {
-        RGBA8,      // 8-bit unorm colour (swapchain / LDR targets)
+        None,       // no attachment (e.g. a target/pipeline with no depth)
+        Swapchain,  // a pipeline's colour target = the presented image (resolved per backend)
+        RGBA8,      // 8-bit unorm colour (LDR / off-screen)
         RGBA16F,    // half-float colour (HDR / cubemap)
         D32,        // 32-bit depth
     };
 
+    // The attachment signature of a render pass / target: a colour format plus an
+    // optional depth format. A pipeline is compatible with any target sharing this
+    // signature, so this is what replaces "which render pass" as an explicit value.
+    struct RenderTargetFormat
+    {
+        Format color = Format::RGBA8;
+        Format depth = Format::None;
+    };
+
+    // The window the device presents into. GLFW is the windowing layer for every
+    // backend, so this carries the GLFWwindow*; each backend derives what it needs
+    // (a GL context, a Vulkan surface, later a CAMetalLayer / HWND) from it. The
+    // RHI names the concept "native window" rather than baking GLFW into its API.
+    struct NativeWindow
+    {
+        void* glfw_handle = nullptr;
+        int   width  = 0;
+        int   height = 0;
+    };
+
     enum class BufferType { Vertex, Index, Uniform };
     enum class Topology   { Triangles, Lines };
     enum class CullMode   { None, Back, Front };
@@ -68,8 +90,7 @@ namespace Donut::RHI
         bool      depth_test  = false;
         bool      depth_write = false;
         CompareOp depth_op    = CompareOp::Less;
-        Format    color_format = Format::RGBA8;   // format of the target it renders into
-        bool      has_depth    = false;           // target has a depth attachment
+        RenderTargetFormat target;   // attachment signature of the pass it draws into
     };
 
     // Records draws for one frame. Obtained from Device::begin_frame (targets the
@@ -102,8 +123,7 @@ namespace Donut::RHI
     public:
         virtual ~Device() = default;
 
-        // glfwWindow: opaque GLFW handle (GL context for OpenGL, NO_API otherwise).
-        virtual auto init(void* glfwWindow, int width, int height) -> bool = 0;
+        virtual auto init(const NativeWindow& window) -> bool = 0;
         virtual auto shutdown() -> void = 0;
         virtual auto resize(int width, int height) -> void = 0;
         virtual auto wait_idle() -> void = 0;
@@ -111,7 +131,7 @@ namespace Donut::RHI
         virtual auto create_buffer(BufferType type, size_t size, const void* data = nullptr) -> Ref<Buffer> = 0;
         virtual auto create_texture(int width, int height, Format format, Filter filter, const void* data = nullptr) -> Ref<Texture> = 0;
         virtual auto create_cubemap_from_hdri(const std::string& equirect_path) -> Ref<Texture> = 0;
-        virtual auto create_render_target(int width, int height, Format color, bool with_depth,
+        virtual auto create_render_target(int width, int height, Format color, Format depth = Format::None,
                                           Filter sample_filter = Filter::Linear, int mip_levels = 1) -> Ref<RenderTarget> = 0;
         virtual auto create_pipeline(const PipelineDesc& desc) -> Ref<Pipeline> = 0;