Apply startup GL state through renderer GL

src/app.cpp

@@ -50,6 +50,26 @@ namespace {
     return static_cast<GLenum>(pp::renderer::gl::scissor_test_state());
 }
 
+void enable_opengl_state(std::uint32_t state) noexcept
+{
+    glEnable(static_cast<GLenum>(state));
+}
+
+void disable_opengl_state(std::uint32_t state) noexcept
+{
+    glDisable(static_cast<GLenum>(state));
+}
+
+void set_opengl_blend_func(std::uint32_t source_factor, std::uint32_t destination_factor) noexcept
+{
+    glBlendFunc(static_cast<GLenum>(source_factor), static_cast<GLenum>(destination_factor));
+}
+
+void set_opengl_blend_equation_separate(std::uint32_t color_equation, std::uint32_t alpha_equation) noexcept
+{
+    glBlendEquationSeparate(static_cast<GLenum>(color_equation), static_cast<GLenum>(alpha_equation));
+}
+
 [[nodiscard]] GLint rgba8_internal_format() noexcept
 {
     return static_cast<GLint>(pp::renderer::gl::rgba8_internal_format());
@@ -389,19 +409,16 @@ void App::init()
         //    }
         //}
     
-        const auto initial_state = pp::renderer::gl::panopainter_initial_state();
-        if (initial_state.depth_test_enabled)
-            glEnable(static_cast<GLenum>(initial_state.depth_test_state));
-        else
-            glDisable(static_cast<GLenum>(initial_state.depth_test_state));
-
         App::I->apply_render_platform_hints();
-        glBlendFunc(
-            static_cast<GLenum>(initial_state.source_color_factor),
-            static_cast<GLenum>(initial_state.destination_color_factor));
-        glBlendEquationSeparate(
-            static_cast<GLenum>(initial_state.color_equation),
-            static_cast<GLenum>(initial_state.alpha_equation));
+        const auto startup_state_status = pp::renderer::gl::apply_panopainter_initial_state(
+            pp::renderer::gl::OpenGlStateDispatch {
+                .enable = enable_opengl_state,
+                .disable = disable_opengl_state,
+                .blend_func = set_opengl_blend_func,
+                .blend_equation_separate = set_opengl_blend_equation_separate,
+            });
+        if (!startup_state_status.ok())
+            LOG("OpenGL startup state failed: %s", startup_state_status.message);
     });
 
     int run_counter = Settings::value<Serializer::Integer>("run_counter") + 1;

src/renderer_gl/opengl_capabilities.cpp

@@ -224,6 +224,27 @@ OpenGlInitialState panopainter_initial_state() noexcept
     };
 }
 
+pp::foundation::Status apply_panopainter_initial_state(OpenGlStateDispatch dispatch) noexcept
+{
+    if (dispatch.enable == nullptr
+        || dispatch.disable == nullptr
+        || dispatch.blend_func == nullptr
+        || dispatch.blend_equation_separate == nullptr)
+    {
+        return pp::foundation::Status::invalid_argument("OpenGL state dispatch callbacks must not be null");
+    }
+
+    const auto state = panopainter_initial_state();
+    if (state.depth_test_enabled)
+        dispatch.enable(state.depth_test_state);
+    else
+        dispatch.disable(state.depth_test_state);
+
+    dispatch.blend_func(state.source_color_factor, state.destination_color_factor);
+    dispatch.blend_equation_separate(state.color_equation, state.alpha_equation);
+    return pp::foundation::Status::success();
+}
+
 std::uint32_t extension_count_query() noexcept
 {
     return gl_num_extensions;

src/renderer_gl/opengl_capabilities.h

@@ -124,12 +124,24 @@ struct OpenGlInitialState {
     std::uint32_t alpha_equation = 0;
 };
 
+using OpenGlCapabilityFn = void (*)(std::uint32_t state) noexcept;
+using OpenGlBlendFuncFn = void (*)(std::uint32_t source_factor, std::uint32_t destination_factor) noexcept;
+using OpenGlBlendEquationSeparateFn = void (*)(std::uint32_t color_equation, std::uint32_t alpha_equation) noexcept;
+
+struct OpenGlStateDispatch {
+    OpenGlCapabilityFn enable = nullptr;
+    OpenGlCapabilityFn disable = nullptr;
+    OpenGlBlendFuncFn blend_func = nullptr;
+    OpenGlBlendEquationSeparateFn blend_equation_separate = nullptr;
+};
+
 [[nodiscard]] OpenGlCapabilities detect_opengl_capabilities(
     std::span<const std::string_view> extensions,
     OpenGlRuntime runtime) noexcept;
 [[nodiscard]] pp::renderer::RenderDeviceFeatures render_device_features(
     OpenGlCapabilities capabilities) noexcept;
 [[nodiscard]] OpenGlInitialState panopainter_initial_state() noexcept;
+[[nodiscard]] pp::foundation::Status apply_panopainter_initial_state(OpenGlStateDispatch dispatch) noexcept;
 
 [[nodiscard]] std::uint32_t extension_count_query() noexcept;
 [[nodiscard]] std::uint32_t extension_string_name() noexcept;