Fix minimap, dialogue boxes, etc. alpha issues

Author: Crementif

resources/BreathOfTheWild_BetterVR/patch_Misc.asm

@@ -3,6 +3,32 @@ moduleMatches = 0x6267BFD0
 
 .origin = codecave
 
+; the game normally draws most of the UI on top of the 3D color buffer
+; the VR mod uses the alpha channel of the 2D UI as a mask to present a transparent version of the HUD on top of the 3D framebuffer
+; this patch basically fixes a few elements not using the right blending options
+; for example, the minimap, dialogue boxes and various other things to overwrite the alpha of previously rendered 2D elements
+; which cause gaps inside the image that's shown in VR
+hook_FixUIBlending:
+stwu r1, -0x10(r1)
+mflr r0
+stw r0, 0x14(r1)
+stw r3, 0xC(r1)
+stw r4, 0x8(r1)
+
+bl import.coreinit.hook_FixUIBlending
+
+bl import.gx2.GX2SetBlendControl
+
+lwz r4, 0x8(r1)
+lwz r3, 0xC(r1)
+lwz r0, 0x14(r1)
+addi r1, r1, 0x10
+mtlr r0
+blr
+
+0x03C58BF8 = bla hook_FixUIBlending
+0x03C58CC0 = bla hook_FixUIBlending
+0x03C58D68 = bla hook_FixUIBlending
 
 ; forces the player to always be guarding when the shield is drawn
 ; uses player rotation to determine the guard direction, not shield direction

src/hooking/cemu_hooks.h

@@ -58,14 +58,15 @@ class CemuHooks {
         osLib_registerHLEFunction("coreinit", "hook_InjectXRInput", &hook_InjectXRInput);
         osLib_registerHLEFunction("coreinit", "hook_XRRumble_VPADControlMotor", &hook_XRRumble_VPADControlMotor);
         osLib_registerHLEFunction("coreinit", "hook_XRRumble_VPADStopMotor", &hook_XRRumble_VPADStopMotor);
+        osLib_registerHLEFunction("coreinit", "hook_FixLadder", &hook_FixLadder);
 
-        // Logging/Debugging Hooks
+        // Misc. Hooks
         osLib_registerHLEFunction("coreinit", "hook_OSReportToConsole", &hook_OSReportToConsole);
         osLib_registerHLEFunction("coreinit", "hook_DropWeaponLogging", &hook_DropWeaponLogging);
         osLib_registerHLEFunction("coreinit", "hook_ModifyHandModelAccessSearch", &hook_ModifyHandModelAccessSearch);
         osLib_registerHLEFunction("coreinit", "hook_CreateNewScreen", &hook_CreateNewScreen);
+        osLib_registerHLEFunction("coreinit", "hook_FixUIBlending", &hook_FixUIBlending);
         osLib_registerHLEFunction("coreinit", "hook_RouteActorJob", &hook_RouteActorJob);
-        osLib_registerHLEFunction("coreinit", "hook_FixLadder", &hook_FixLadder);
     };
     ~CemuHooks() {
         FreeLibrary(m_cemuHandle);
@@ -232,11 +233,12 @@ class CemuHooks {
     static void hook_XRRumble_VPADControlMotor(PPCInterpreter_t* hCPU);
     static void hook_XRRumble_VPADStopMotor(PPCInterpreter_t* hCPU);
 
-    // Logging/Debugging Hooks
+    // Misc Hooks
     static void hook_OSReportToConsole(PPCInterpreter_t* hCPU);
     static void hook_DropWeaponLogging(PPCInterpreter_t* hCPU);
     static void hook_ModifyHandModelAccessSearch(PPCInterpreter_t* hCPU);
     static void hook_CreateNewScreen(PPCInterpreter_t* hCPU);
+    static void hook_FixUIBlending(PPCInterpreter_t* hCPU);
     static void hook_RouteActorJob(PPCInterpreter_t* hCPU);
 
 public:

src/hooking/weapon.cpp

@@ -242,6 +242,65 @@ void CemuHooks::hook_CreateNewScreen(PPCInterpreter_t* hCPU) {
     }
 }
 
+
+enum class GX2_BLENDFACTOR {
+    ZERO = 0x00,
+    ONE = 0x01,
+    SRC_COLOR = 0x02,
+    ONE_MINUS_SRC_COLOR = 0x03,
+    SRC_ALPHA = 0x04,
+    ONE_MINUS_SRC_ALPHA = 0x05,
+    DST_ALPHA = 0x06,
+    ONE_MINUS_DST_ALPHA = 0x07,
+    DST_COLOR = 0x08,
+    ONE_MINUS_DST_COLOR = 0x09,
+    SRC_ALPHA_SATURATE = 0x0A,
+    BOTH_SRC_ALPHA = 0x0B,
+    BOTH_INV_SRC_ALPHA = 0x0C,
+    CONST_COLOR = 0x0D,
+    ONE_MINUS_CONST_COLOR = 0x0E,
+    SRC1_COLOR = 0x0F,
+    INV_SRC1_COLOR = 0x10,
+    SRC1_ALPHA = 0x11,
+    INV_SRC1_ALPHA = 0x12,
+    CONST_ALPHA = 0x13,
+    ONE_MINUS_CONST_ALPHA = 0x14
+};
+
+enum class GX2_COMBINEFUNC {
+    DST_PLUS_SRC = 0,
+    SRC_MINUS_DST = 1,
+    MIN_DST_SRC = 2,
+    MAX_DST_SRC = 3,
+    DST_MINUS_SRC = 4
+};
+
+void CemuHooks::hook_FixUIBlending(PPCInterpreter_t* hCPU) {
+    hCPU->instructionPointer = hCPU->sprNew.LR;
+
+    uint32_t renderTargetIndex = hCPU->gpr[3];
+    GX2_BLENDFACTOR colorSrcFactor = (GX2_BLENDFACTOR)hCPU->gpr[4];
+    GX2_BLENDFACTOR colorDstFactor = (GX2_BLENDFACTOR)hCPU->gpr[5];
+    GX2_COMBINEFUNC colorCombineFunc = (GX2_COMBINEFUNC)hCPU->gpr[6];
+    uint32_t separateAlphaBlend = hCPU->gpr[7];
+    GX2_BLENDFACTOR alphaSrcFactor = (GX2_BLENDFACTOR)hCPU->gpr[8];
+    GX2_BLENDFACTOR alphaDstFactor = (GX2_BLENDFACTOR)hCPU->gpr[9];
+    GX2_COMBINEFUNC alphaCombineFunc = (GX2_COMBINEFUNC)hCPU->gpr[10];
+
+    {
+        bool matchesColorSettings = colorSrcFactor == GX2_BLENDFACTOR::DST_COLOR && colorDstFactor == GX2_BLENDFACTOR::SRC_ALPHA && colorCombineFunc == GX2_COMBINEFUNC::DST_PLUS_SRC;
+        bool matchesAlpha = alphaSrcFactor == GX2_BLENDFACTOR::SRC_ALPHA && alphaDstFactor == GX2_BLENDFACTOR::ONE_MINUS_SRC_ALPHA && alphaCombineFunc == GX2_COMBINEFUNC::DST_PLUS_SRC;
+
+        if (matchesColorSettings && matchesAlpha) {
+            hCPU->gpr[7] = 1;
+            hCPU->gpr[8] = std::to_underlying(GX2_BLENDFACTOR::ZERO);
+            hCPU->gpr[9] = std::to_underlying(GX2_BLENDFACTOR::DST_ALPHA);
+
+            //Log::print<VERBOSE>("FixUIBlending called with renderTargetIndex: {}, colorSrcFactor: {}, colorDstFactor: {}, colorCombineFunc: {}, separateAlphaBlend: {}, alphaSrcFactor: {}, alphaDstFactor: {}, alphaCombineFunc: {}", renderTargetIndex, std::to_underlying(colorSrcFactor), std::to_underlying(colorDstFactor), std::to_underlying(colorCombineFunc), separateAlphaBlend, std::to_underlying(alphaSrcFactor), std::to_underlying(alphaDstFactor), std::to_underlying(alphaCombineFunc));
+        }
+    }
+}
+
 // todo: this function does nothing, we use ChangeWeaponMtx instead
 void CemuHooks::hook_DropEquipment(PPCInterpreter_t* hCPU) {
     hCPU->instructionPointer = hCPU->sprNew.LR;