Route framebuffer texture copies through GL backend

src/renderer_gl/opengl_capabilities.cpp

@@ -748,6 +748,36 @@ pp::foundation::Status update_opengl_texture_2d(
     return pp::foundation::Status::success();
 }
 
+pp::foundation::Status copy_opengl_framebuffer_to_texture_2d(
+    OpenGlTexture2DFramebufferCopy copy,
+    OpenGlTexture2DFramebufferCopyDispatch dispatch) noexcept
+{
+    if (dispatch.copy_tex_sub_image_2d == nullptr) {
+        return pp::foundation::Status::invalid_argument(
+            "OpenGL framebuffer-to-texture copy dispatch callback must not be null");
+    }
+
+    if (copy.width < 0 || copy.height < 0) {
+        return pp::foundation::Status::invalid_argument(
+            "OpenGL framebuffer-to-texture copy dimensions are invalid");
+    }
+
+    if (copy.width == 0 || copy.height == 0) {
+        return pp::foundation::Status::success();
+    }
+
+    dispatch.copy_tex_sub_image_2d(
+        texture_2d_target(),
+        copy.level,
+        copy.destination_x,
+        copy.destination_y,
+        copy.source_x,
+        copy.source_y,
+        copy.width,
+        copy.height);
+    return pp::foundation::Status::success();
+}
+
 pp::foundation::Status generate_opengl_texture_2d_mipmaps(
     std::uint32_t texture_id,
     OpenGlTexture2DMipmapDispatch dispatch) noexcept

src/renderer_gl/opengl_capabilities.h

@@ -149,6 +149,16 @@ struct OpenGlTexture2DUpdate {
     const void* data = nullptr;
 };
 
+struct OpenGlTexture2DFramebufferCopy {
+    std::int32_t level = 0;
+    std::int32_t destination_x = 0;
+    std::int32_t destination_y = 0;
+    std::int32_t source_x = 0;
+    std::int32_t source_y = 0;
+    std::int32_t width = 0;
+    std::int32_t height = 0;
+};
+
 struct OpenGlTexture2DReadback {
     std::uint32_t texture_id = 0;
     std::int32_t width = 0;
@@ -426,6 +436,15 @@ using OpenGlTexSubImage2DFn = void (*)(
     std::uint32_t pixel_format,
     std::uint32_t component_type,
     const void* data) noexcept;
+using OpenGlCopyTexSubImage2DFn = void (*)(
+    std::uint32_t target,
+    std::int32_t level,
+    std::int32_t destination_x,
+    std::int32_t destination_y,
+    std::int32_t source_x,
+    std::int32_t source_y,
+    std::int32_t width,
+    std::int32_t height) noexcept;
 using OpenGlGenerateMipmapFn = void (*)(std::uint32_t target) noexcept;
 using OpenGlFramebufferTexture2DFn = void (*)(
     std::uint32_t target,
@@ -582,6 +601,10 @@ struct OpenGlTexture2DUpdateDispatch {
     OpenGlTexSubImage2DFn tex_sub_image_2d = nullptr;
 };
 
+struct OpenGlTexture2DFramebufferCopyDispatch {
+    OpenGlCopyTexSubImage2DFn copy_tex_sub_image_2d = nullptr;
+};
+
 struct OpenGlTexture2DMipmapDispatch {
     OpenGlBindTextureFn bind_texture = nullptr;
     OpenGlGenerateMipmapFn generate_mipmap = nullptr;
@@ -820,6 +843,9 @@ struct OpenGlMeshDeleteDispatch {
 [[nodiscard]] pp::foundation::Status update_opengl_texture_2d(
     OpenGlTexture2DUpdate update,
     OpenGlTexture2DUpdateDispatch dispatch) noexcept;
+[[nodiscard]] pp::foundation::Status copy_opengl_framebuffer_to_texture_2d(
+    OpenGlTexture2DFramebufferCopy copy,
+    OpenGlTexture2DFramebufferCopyDispatch dispatch) noexcept;
 [[nodiscard]] pp::foundation::Status generate_opengl_texture_2d_mipmaps(
     std::uint32_t texture_id,
     OpenGlTexture2DMipmapDispatch dispatch) noexcept;