implement proper support for POWCNT1.

fixes #260

8 files changed, 137 insertions, 47 deletions

diff --git a/src/GPU.cpp b/src/GPU.cpp
index aba97a5..ba04c84 100644
--- a/src/GPU.cpp
+++ b/src/GPU.cpp
@@ -650,9 +650,23 @@ void MapVRAM_I(u32 bank, u8 cnt)
 }
 
 
-void DisplaySwap(u32 val)
+void SetPowerCnt(u32 val)
 {
-    if (val)
+    // POWCNT1 effects:
+    // * bit0: asplodes hardware??? not tested.
+    // * bit1: disables engine A palette and OAM (zero-filled) (TODO: affects mem timings???)
+    // * bit2: disables rendering engine, resets its internal state (polygons and registers)
+    // * bit3: disables geometry engine
+    // * bit9: disables engine B palette, OAM and rendering (screen turns white)
+    // * bit15: screen swap
+
+    if (!(val & (1<<0))) printf("!!! CLEARING POWCNT BIT0. DANGER\n");
+
+    GPU2D_A->SetEnabled(val & (1<<1));
+    GPU2D_B->SetEnabled(val & (1<<9));
+    GPU3D::SetEnabled(val & (1<<3), val & (1<<2));
+
+    if (val & (1<<15))
     {
         GPU2D_A->SetFramebuffer(&Framebuffer[256*0]);
         GPU2D_B->SetFramebuffer(&Framebuffer[256*192]);
@@ -838,6 +852,7 @@ void SetVCount(u16 val)
     // VCount write is delayed until the next scanline
 
     // TODO: how does the 3D engine react to VCount writes while it's rendering?
+    // 3D engine seems to give up on the current frame in that situation, repeating the last two scanlines
     // TODO: also check the various DMA types that can be involved
 
     NextVCount = val;
diff --git a/src/GPU.h b/src/GPU.h
index 2ef33d9..6f5733d 100644
--- a/src/GPU.h
+++ b/src/GPU.h
@@ -387,7 +387,7 @@ T ReadVRAM_TexPal(u32 addr)
 }
 
 
-void DisplaySwap(u32 val);
+void SetPowerCnt(u32 val);
 
 void StartFrame();
 void FinishFrame(u32 lines);
diff --git a/src/GPU2D.cpp b/src/GPU2D.cpp
index 4951404..f7e834d 100644
--- a/src/GPU2D.cpp
+++ b/src/GPU2D.cpp
@@ -273,6 +273,8 @@ u32 GPU2D::Read32(u32 addr)
 
 void GPU2D::Write8(u32 addr, u8 val)
 {
+    if (!Enabled) return;
+
     switch (addr & 0x00000FFF)
     {
     case 0x000: DispCnt = (DispCnt & 0xFFFFFF00) | val; return;
@@ -353,6 +355,8 @@ void GPU2D::Write8(u32 addr, u8 val)
 
 void GPU2D::Write16(u32 addr, u16 val)
 {
+    if (!Enabled) return;
+
     switch (addr & 0x00000FFF)
     {
     case 0x000: DispCnt = (DispCnt & 0xFFFF0000) | val; return;
@@ -482,6 +486,8 @@ void GPU2D::Write16(u32 addr, u16 val)
 
 void GPU2D::Write32(u32 addr, u32 val)
 {
+    if (!Enabled) return;
+
     switch (addr & 0x00000FFF)
     {
     case 0x000:
@@ -542,19 +548,21 @@ void GPU2D::DrawScanline(u32 line)
 
     line = GPU::VCount;
 
+    bool forceblank = false;
+
     // scanlines that end up outside of the GPU drawing range
     // (as a result of writing to VCount) are filled white
-    if (line > 192)
-    {
-        for (int i = 0; i < 256; i++)
-            dst[i] = 0xFFFFFFFF;
+    if (line > 192) forceblank = true;
 
-        return;
-    }
+    // GPU B can be completely disabled by POWCNT1
+    // oddly that's not the case for GPU A
+    if (Num && !Enabled) forceblank = true;
 
     // forced blank
     // (checkme: are there still things that can run under this mode? likely not)
-    if (DispCnt & (1<<7))
+    if (DispCnt & (1<<7)) forceblank = true;
+
+    if (forceblank)
     {
         for (int i = 0; i < 256; i++)
             dst[i] = 0xFFFFFFFF;
diff --git a/src/GPU2D.h b/src/GPU2D.h
index 5a1192e..1776680 100644
--- a/src/GPU2D.h
+++ b/src/GPU2D.h
@@ -29,6 +29,7 @@ public:
 
     void DoSavestate(Savestate* file);
 
+    void SetEnabled(bool enable) { Enabled = enable; }
     void SetFramebuffer(u32* buf);
 
     u8 Read8(u32 addr);
@@ -64,6 +65,7 @@ public:
 
 private:
     u32 Num;
+    bool Enabled;
     u32* Framebuffer;
 
     u16 DispFIFO[16];
diff --git a/src/GPU3D.cpp b/src/GPU3D.cpp
index bc1ab1b..3b69577 100644
--- a/src/GPU3D.cpp
+++ b/src/GPU3D.cpp
@@ -152,6 +152,9 @@ FIFO<CmdFIFOEntry>* CmdStallQueue;
 
 u32 NumCommands, CurCommand, ParamCount, TotalParams;
 
+bool GeometryEnabled;
+bool RenderingEnabled;
+
 u32 DispCnt;
 u8 AlphaRefVal, AlphaRef;
 
@@ -285,6 +288,25 @@ void DeInit()
     delete CmdStallQueue;
 }
 
+void ResetRenderingState()
+{
+    RenderNumPolygons = 0;
+
+    RenderDispCnt = 0;
+    RenderAlphaRef = 0;
+
+    memset(RenderEdgeTable, 0, 8*2);
+    memset(RenderToonTable, 0, 32*2);
+
+    RenderFogColor = 0;
+    RenderFogOffset = 0;
+    RenderFogShift = 0;
+    memset(RenderFogDensityTable, 0, 34);
+
+    RenderClearAttr1 = 0x3F000000;
+    RenderClearAttr2 = 0x00007FFF;
+}
+
 void Reset()
 {
     CmdFIFO->Clear();
@@ -356,6 +378,7 @@ void Reset()
     FlushRequest = 0;
     FlushAttributes = 0;
 
+    ResetRenderingState();
     SoftRenderer::Reset();
 }
 
@@ -556,6 +579,16 @@ void DoSavestate(Savestate* file)
 
 
 
+void SetEnabled(bool geometry, bool rendering)
+{
+    GeometryEnabled = geometry;
+    RenderingEnabled = rendering;
+
+    if (!rendering) ResetRenderingState();
+}
+
+
+
 void MatrixLoadIdentity(s32* m)
 {
     m[0] = 0x1000; m[1] = 0;      m[2] = 0;       m[3] = 0;
@@ -2213,6 +2246,8 @@ void FinishWork(s32 cycles)
 
 void Run(s32 cycles)
 {
+    if (!GeometryEnabled)
+        return;
     if (FlushRequest)
         return;
     if (CmdPIPE->IsEmpty() && !(GXStat & (1<<27)))
@@ -2281,46 +2316,49 @@ bool YSort(Polygon* a, Polygon* b)
 
 void VBlank()
 {
-    if (FlushRequest)
+    if (GeometryEnabled && FlushRequest)
     {
-        if (NumPolygons)
+        if (RenderingEnabled)
         {
-            // separate translucent polygons from opaque ones
-
-            u32 io = 0, it = NumOpaquePolygons;
-            for (u32 i = 0; i < NumPolygons; i++)
+            if (NumPolygons)
             {
-                Polygon* poly = &CurPolygonRAM[i];
-                if (poly->Translucent)
-                    RenderPolygonRAM[it++] = poly;
-                else
-                    RenderPolygonRAM[io++] = poly;
-            }
+                // separate translucent polygons from opaque ones
+
+                u32 io = 0, it = NumOpaquePolygons;
+                for (u32 i = 0; i < NumPolygons; i++)
+                {
+                    Polygon* poly = &CurPolygonRAM[i];
+                    if (poly->Translucent)
+                        RenderPolygonRAM[it++] = poly;
+                    else
+                        RenderPolygonRAM[io++] = poly;
+                }
 
-            // apply Y-sorting
+                // apply Y-sorting
 
-            std::stable_sort(RenderPolygonRAM.begin(),
-                RenderPolygonRAM.begin() + ((FlushAttributes & 0x1) ? NumOpaquePolygons : NumPolygons),
-                YSort);
-        }
+                std::stable_sort(RenderPolygonRAM.begin(),
+                    RenderPolygonRAM.begin() + ((FlushAttributes & 0x1) ? NumOpaquePolygons : NumPolygons),
+                    YSort);
+            }
 
-        RenderNumPolygons = NumPolygons;
+            RenderNumPolygons = NumPolygons;
 
-        RenderDispCnt = DispCnt;
-        RenderAlphaRef = AlphaRef;
+            RenderDispCnt = DispCnt;
+            RenderAlphaRef = AlphaRef;
 
-        memcpy(RenderEdgeTable, EdgeTable, 8*2);
-        memcpy(RenderToonTable, ToonTable, 32*2);
+            memcpy(RenderEdgeTable, EdgeTable, 8*2);
+            memcpy(RenderToonTable, ToonTable, 32*2);
 
-        RenderFogColor = FogColor;
-        RenderFogOffset = FogOffset * 0x200;
-        RenderFogShift = (RenderDispCnt >> 8) & 0xF;
-        RenderFogDensityTable[0] = FogDensityTable[0];
-        memcpy(&RenderFogDensityTable[1], FogDensityTable, 32);
-        RenderFogDensityTable[33] = FogDensityTable[31];
+            RenderFogColor = FogColor;
+            RenderFogOffset = FogOffset * 0x200;
+            RenderFogShift = (RenderDispCnt >> 8) & 0xF;
+            RenderFogDensityTable[0] = FogDensityTable[0];
+            memcpy(&RenderFogDensityTable[1], FogDensityTable, 32);
+            RenderFogDensityTable[33] = FogDensityTable[31];
 
-        RenderClearAttr1 = ClearAttr1;
-        RenderClearAttr2 = ClearAttr2;
+            RenderClearAttr1 = ClearAttr1;
+            RenderClearAttr2 = ClearAttr2;
+        }
 
         CurRAMBank = CurRAMBank?0:1;
         CurVertexRAM = &VertexRAM[CurRAMBank ? 6144 : 0];
@@ -2515,6 +2553,9 @@ u32 Read32(u32 addr)
 
 void Write8(u32 addr, u8 val)
 {
+    if (!RenderingEnabled && addr >= 0x04000320 && addr < 0x04000400) return;
+    if (!GeometryEnabled  && addr >= 0x04000400 && addr < 0x04000700) return;
+
     switch (addr)
     {
     case 0x04000340:
@@ -2550,6 +2591,9 @@ void Write8(u32 addr, u8 val)
 
 void Write16(u32 addr, u16 val)
 {
+    if (!RenderingEnabled && addr >= 0x04000320 && addr < 0x04000400) return;
+    if (!GeometryEnabled  && addr >= 0x04000400 && addr < 0x04000700) return;
+
     switch (addr)
     {
     case 0x04000060:
@@ -2629,6 +2673,9 @@ void Write16(u32 addr, u16 val)
 
 void Write32(u32 addr, u32 val)
 {
+    if (!RenderingEnabled && addr >= 0x04000320 && addr < 0x04000400) return;
+    if (!GeometryEnabled  && addr >= 0x04000400 && addr < 0x04000700) return;
+
     switch (addr)
     {
     case 0x04000060:
diff --git a/src/GPU3D.h b/src/GPU3D.h
index b74e421..d510d30 100644
--- a/src/GPU3D.h
+++ b/src/GPU3D.h
@@ -88,6 +88,8 @@ void Reset();
 
 void DoSavestate(Savestate* file);
 
+void SetEnabled(bool geometry, bool rendering);
+
 void ExecuteCommand();
 
 s32 CyclesToRunFor();
diff --git a/src/GPU3D_Soft.cpp b/src/GPU3D_Soft.cpp
index daf5cdd..923348a 100644
--- a/src/GPU3D_Soft.cpp
+++ b/src/GPU3D_Soft.cpp
@@ -56,6 +56,8 @@ u32 AttrBuffer[BufferSize * 2];
 u8 StencilBuffer[256*2];
 bool PrevIsShadowMask;
 
+bool Enabled;
+
 // threading
 
 void* RenderThread;
@@ -137,6 +139,7 @@ void Reset()
 }
 
 
+
 // Notes on the interpolator:
 //
 // This is a theory on how the DS hardware interpolates values. It matches hardware output
diff --git a/src/NDS.cpp b/src/NDS.cpp
index 07273d7..aa8b1d3 100644
--- a/src/NDS.cpp
+++ b/src/NDS.cpp
@@ -363,7 +363,7 @@ void SetupDirectBoot()
     PostFlag7 = 0x01;
 
     PowerControl9 = 0x820F;
-    GPU::DisplaySwap(PowerControl9);
+    GPU::SetPowerCnt(PowerControl9);
 
     // checkme
     RCnt = 0x8000;
@@ -678,8 +678,6 @@ bool DoSavestate(Savestate* file)
 
     if (!file->Saving)
     {
-        GPU::DisplaySwap(PowerControl9>>15);
-
         InitTimings();
         SetGBASlotTimings();
 
@@ -698,6 +696,11 @@ bool DoSavestate(Savestate* file)
     RTC::DoSavestate(file);
     Wifi::DoSavestate(file);
 
+    if (!file->Saving)
+    {
+        GPU::SetPowerCnt(PowerControl9);
+    }
+
     return true;
 }
 
@@ -1618,6 +1621,7 @@ u8 ARM9Read8(u32 addr)
         return ARM9IORead8(addr);
 
     case 0x05000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return 0;
         return *(u8*)&GPU::Palette[addr & 0x7FF];
 
     case 0x06000000:
@@ -1631,6 +1635,7 @@ u8 ARM9Read8(u32 addr)
         }
 
     case 0x07000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return 0;
         return *(u8*)&GPU::OAM[addr & 0x7FF];
 
     case 0x08000000:
@@ -1677,6 +1682,7 @@ u16 ARM9Read16(u32 addr)
         return ARM9IORead16(addr);
 
     case 0x05000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return 0;
         return *(u16*)&GPU::Palette[addr & 0x7FF];
 
     case 0x06000000:
@@ -1690,6 +1696,7 @@ u16 ARM9Read16(u32 addr)
         }
 
     case 0x07000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return 0;
         return *(u16*)&GPU::OAM[addr & 0x7FF];
 
     case 0x08000000:
@@ -1736,6 +1743,7 @@ u32 ARM9Read32(u32 addr)
         return ARM9IORead32(addr);
 
     case 0x05000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return 0;
         return *(u32*)&GPU::Palette[addr & 0x7FF];
 
     case 0x06000000:
@@ -1749,6 +1757,7 @@ u32 ARM9Read32(u32 addr)
         }
 
     case 0x07000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return 0;
         return *(u32*)&GPU::OAM[addr & 0x7FF];
 
     case 0x08000000:
@@ -1818,6 +1827,7 @@ void ARM9Write16(u32 addr, u16 val)
         return;
 
     case 0x05000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return;
         *(u16*)&GPU::Palette[addr & 0x7FF] = val;
         return;
 
@@ -1832,6 +1842,7 @@ void ARM9Write16(u32 addr, u16 val)
         }
 
     case 0x07000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return;
         *(u16*)&GPU::OAM[addr & 0x7FF] = val;
         return;
     }
@@ -1859,6 +1870,7 @@ void ARM9Write32(u32 addr, u32 val)
         return;
 
     case 0x05000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return;
         *(u32*)&GPU::Palette[addr & 0x7FF] = val;
         return;
 
@@ -1873,6 +1885,7 @@ void ARM9Write32(u32 addr, u32 val)
         }
 
     case 0x07000000:
+        if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return;
         *(u32*)&GPU::OAM[addr & 0x7FF] = val;
         return;
     }
@@ -2809,8 +2822,8 @@ void ARM9IOWrite16(u32 addr, u16 val)
         return;
 
     case 0x04000304:
-        PowerControl9 = val;
-        GPU::DisplaySwap(PowerControl9>>15);
+        PowerControl9 = val & 0x820F;
+        GPU::SetPowerCnt(PowerControl9);
         return;
     }
 
@@ -2962,8 +2975,8 @@ void ARM9IOWrite32(u32 addr, u32 val)
     case 0x040002BC: SqrtVal[1] = val; StartSqrt(); return;
 
     case 0x04000304:
-        PowerControl9 = val & 0xFFFF;
-        GPU::DisplaySwap(PowerControl9>>15);
+        PowerControl9 = val & 0x820F;
+        GPU::SetPowerCnt(PowerControl9);
         return;
     }