improve imgui integration

neo/sys/events.cpp

@@ -1125,7 +1125,10 @@ sysEvent_t Sys_GetEvent() {
 
 	// loop until there is an event we care about (will return then) or no more events
 	while(SDL_PollEvent(&ev)) {
-		D3::ImGuiHooks::ProcessEvent(&ev);
+		if(D3::ImGuiHooks::ProcessEvent(&ev)) {
+			// ImGui has used the event, so it shouldn't also be handled by the game
+			continue;
+		}
 
 		switch (ev.type) {
 #if SDL_VERSION_ATLEAST(2, 0, 0)

neo/sys/sys_imgui.cpp

@@ -10,6 +10,7 @@
 
 #include "framework/Common.h"
 #include "renderer/qgl.h"
+#include "renderer/tr_local.h" // glconfig
 
 
 namespace D3 {
@@ -21,11 +22,6 @@ static bool haveNewFrame = false;
 // using void* instead of SDL_Window and SDL_GLContext to avoid dragging SDL headers into sys_imgui.h
 bool Init(void* sdlWindow, void* sdlGlContext)
 {
-	SDL_Window* win = (SDL_Window*)sdlWindow;
-	SDL_GL_MakeCurrent(win, (SDL_GLContext)sdlGlContext); // XXX: really?
-	//SDL_GLContext glctx = (SDL_GLContext)sdlGlContext;
-	SDL_GL_SetSwapInterval(1); // XXX: really?
-
 	common->Printf( "Initializing ImGui\n" );
 
 	// Setup Dear ImGui context
@@ -42,9 +38,22 @@ bool Init(void* sdlWindow, void* sdlGlContext)
 	// Setup Dear ImGui style
 	ImGui::StyleColorsDark();
 	//ImGui::StyleColorsLight();
+	//ImGui::StyleColorsClassic();
+
+	// make it a bit prettier with rounded edges
+	ImGuiStyle& style = ImGui::GetStyle();
+	style.WindowRounding = 2.0f;
+	style.FrameRounding = 3.0f;
+	//style.ChildRounding = 6.0f;
+	style.ScrollbarRounding = 8.0f;
+	style.GrabRounding = 1.0f;
+	style.PopupRounding = 2.0f;
+
+	ImVec4* colors = style.Colors;
+	colors[ImGuiCol_TitleBg]                = ImVec4(0.28f, 0.36f, 0.48f, 0.88f);
 
 	// Setup Platform/Renderer backends
-	if (!ImGui_ImplSDL2_InitForOpenGL(win, sdlGlContext)) {
+	if ( ! ImGui_ImplSDL2_InitForOpenGL( (SDL_Window*)sdlWindow, sdlGlContext ) ) {
 		ImGui::DestroyContext( imguiCtx );
 		imguiCtx = NULL;
 		common->Warning( "Failed to initialize ImGui SDL platform backend!\n" );
@@ -136,9 +145,37 @@ void NewFrame()
 	}
 }
 
+// returns true if ImGui has handled the event and it shouldn't be passed to the game
 bool ProcessEvent(const void* sdlEvent)
 {
-	return ImGui_ImplSDL2_ProcessEvent( (const SDL_Event*)sdlEvent );
+	const SDL_Event* ev = (const SDL_Event*)sdlEvent;
+	// ImGui_ImplSDL2_ProcessEvent() doc says:
+	//   You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
+	//   - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
+	//   - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
+	//   Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+	if( ImGui_ImplSDL2_ProcessEvent( ev ) ) {
+		ImGuiIO& io = ImGui::GetIO();
+		if ( io.WantCaptureMouse ) {
+			switch( ev->type ) {
+				case SDL_MOUSEMOTION:
+				case SDL_MOUSEWHEEL:
+				case SDL_MOUSEBUTTONDOWN:
+				case SDL_MOUSEBUTTONUP:
+					return true;
+			}
+		}
+
+		if ( io.WantCaptureKeyboard ) {
+			switch( ev->type ) {
+				case SDL_TEXTINPUT:
+				case SDL_KEYDOWN:
+				case SDL_KEYUP:
+					return true;
+			}
+		}
+	}
+	return false;
 }
 
 void EndFrame()
@@ -149,32 +186,40 @@ void EndFrame()
 	}
 	haveNewFrame = false;
 	ImGui::Render();
-	ImGuiIO& io = ImGui::GetIO();
-	//qglViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-	//ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-	//qglClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-	//qglClear(GL_COLOR_BUFFER_BIT);
 
+	// Doom3 uses the OpenGL ARB shader extensions, for most things it renders.
+	// disable those shaders, the OpenGL classic integration of ImGui doesn't use shaders
 	qglDisable( GL_VERTEX_PROGRAM_ARB );
 	qglDisable( GL_FRAGMENT_PROGRAM_ARB );
 
-	GLint curArrayBuffer = 0, curElemBuffer = 0;
+	// Doom3 uses OpenGL's ARB_vertex_buffer_object extension to use VBOs on the GPU
+	// as buffers for glDrawElements() (instead of passing userspace buffers to that function)
+	// ImGui however uses userspace buffers, so remember the currently bound VBO
+	// and unbind it (after drawing, bind it again)
+	GLint curArrayBuffer = 0;
+	if ( glConfig.ARBVertexBufferObjectAvailable ) {
 		qglGetIntegerv( GL_ARRAY_BUFFER_BINDING_ARB, &curArrayBuffer );
-	qglGetIntegerv( GL_ELEMENT_ARRAY_BUFFER_BINDING_ARB, &curElemBuffer );
-
 		qglBindBufferARB( GL_ARRAY_BUFFER_ARB, 0 );
-	qglBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, 0 );
+	}
 
+	// disable all texture units, ImGui_ImplOpenGL2_RenderDrawData() will enable texture 0
+	// and bind its own textures to it as needed
+	for ( int i = glConfig.maxTextureUnits - 1 ; i >= 0 ; i-- ) {
+		GL_SelectTexture( i );
+		qglDisable( GL_TEXTURE_2D );
+		if ( glConfig.texture3DAvailable ) {
+			qglDisable( GL_TEXTURE_3D );
+		}
+		if ( glConfig.cubeMapAvailable ) {
+			qglDisable( GL_TEXTURE_CUBE_MAP_EXT );
+		}
+	}
 
-	ImDrawData* drawData = ImGui::GetDrawData();
+	ImGui_ImplOpenGL2_RenderDrawData( ImGui::GetDrawData() );
-	ImGui_ImplOpenGL2_RenderDrawData( drawData );
 
 	if ( curArrayBuffer != 0 ) {
 		qglBindBufferARB( GL_ARRAY_BUFFER_ARB, curArrayBuffer );
 	}
-	if( curElemBuffer != 0 ) {
-		qglBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, curElemBuffer );
-	}
 }
 
 }} //namespace D3::ImGuiHooks