implement mask blendmode

libstarlight/source/starlight/gfx/RenderCore.cpp

@@ -152,8 +152,9 @@ void RenderCore::EndFrame() {
 namespace {
     void ApplyBlendMode(C3D_TexEnv* env, BlendMode mode) {
         switch(mode) {
-            case BlendMode::Mask: // TODO: actually implement masking! this is just a copy of Blend right now
-                C3D_TexEnvOp(env, C3D_RGB, 0, 0, 0);
+            case BlendMode::Mask: // multiplies the buffer contents by the mask texture
+                C3D_AlphaBlend(GPU_BLEND_ADD, GPU_BLEND_ADD, GPU_ZERO, GPU_SRC_COLOR, GPU_ZERO, GPU_SRC_ALPHA); // zero + (buffer * texel)
+                C3D_TexEnvOp(env, C3D_RGB, 0, 0, 0); // and the rest is the same as blend
                 C3D_TexEnvOp(env, C3D_Alpha, GPU_TEVOP_A_SRC_ALPHA, GPU_TEVOP_A_SRC_ALPHA, 0);
                 C3D_TexEnvFunc(env, C3D_RGB, GPU_MODULATE);
                 C3D_TexEnvFunc(env, C3D_Alpha, GPU_MODULATE);

libstarlight/source/starlight/ui/Label.cpp

@@ -54,6 +54,10 @@ void Label::PreDraw() {
         buffer->Clear();
         GFXManager::PushContext(buffer.get());
         textConfig.ROGet().Print(buffer->rect, text);
+        static auto testmask = 
+            //ThemeManager::GetAsset("controls/button.idle");
+            ThemeManager::GetAsset("decorations/testmask");
+        testmask->Draw(buffer->rect, nullptr, nullptr, gfx::BlendMode::Mask);
         GFXManager::PopContext();
     }
 }

libstarlight/todo.txt

@@ -8,7 +8,7 @@ roadmap to v0.5.1 {
         https://github.com/citra-emu/citra/issues/2684
     implement more blend modes {
         - flat replace
-        masking
+        - masking
     }
     
     - fix the hang on osk when pressing (L|R)+up+left
@@ -28,6 +28,7 @@ roadmap to v0.5.1 {
         Trackable sideclass for threads; float progress 0..1, etc.
         - MAKE THREADS END CLEANLY
         ^ observed a single instance of being stalled on redscreen, not really sure what that was about
+        lambda task thread
     }
 } then by v0.5.5 {
     event propagation system of some sort; threadsafe to whatever extent is needed on 3DS