split framebuffer.

setup doublebuffering inside GPU.cpp.
avoid copying a whole framebuffer every frame. better performance at higher res.

4 files changed, 91 insertions, 37 deletions

diff --git a/src/GPU.cpp b/src/GPU.cpp
index f272129..636c430 100644
--- a/src/GPU.cpp
+++ b/src/GPU.cpp
@@ -71,9 +71,9 @@ u32 VRAMMap_TexPal[8];
 
 u32 VRAMMap_ARM7[2];
 
-u32* Framebuffer;
-int FBScale;
-int FBScreenStride;
+int FrontBuffer;
+u32* Framebuffer[2][2];
+int FBScale[2];
 
 GPU2D* GPU2D_A;
 GPU2D* GPU2D_B;
@@ -85,8 +85,12 @@ bool Init()
     GPU2D_B = new GPU2D(1);
     if (!GPU3D::Init()) return false;
 
+    FrontBuffer = 0;
+    Framebuffer[0][0] = NULL; Framebuffer[0][1] = NULL;
+    Framebuffer[1][0] = NULL; Framebuffer[1][1] = NULL;
+    FBScale[0] = -1; FBScale[1] = -1;
     //SetFramebufferScale(1);
-    SetFramebufferScale(2);
+    SetFramebufferScale(1, 1);
 
     return true;
 }
@@ -97,7 +101,10 @@ void DeInit()
     delete GPU2D_B;
     GPU3D::DeInit();
 
-    if (Framebuffer) delete[] Framebuffer;
+    if (Framebuffer[0][0]) delete[] Framebuffer[0][0];
+    if (Framebuffer[0][1]) delete[] Framebuffer[0][1];
+    if (Framebuffer[1][0]) delete[] Framebuffer[1][0];
+    if (Framebuffer[1][1]) delete[] Framebuffer[1][1];
 }
 
 void Reset()
@@ -145,22 +152,32 @@ void Reset()
     VRAMMap_ARM7[0] = 0;
     VRAMMap_ARM7[1] = 0;
 
-    for (int i = 0; i < 256*192*2; i++)
+    for (int i = 0; i < (256*192)<<(FBScale[0]*2); i++)
     {
-        Framebuffer[i] = 0xFFFFFFFF;
+        Framebuffer[0][0][i] = 0xFFFFFFFF;
+        Framebuffer[1][0][i] = 0xFFFFFFFF;
+    }
+    for (int i = 0; i < (256*192)<<(FBScale[1]*2); i++)
+    {
+        Framebuffer[0][1][i] = 0xFFFFFFFF;
+        Framebuffer[1][1][i] = 0xFFFFFFFF;
     }
 
     GPU2D_A->Reset();
     GPU2D_B->Reset();
     GPU3D::Reset();
 
-    GPU2D_A->SetFramebuffer(&Framebuffer[FBScreenStride]);
-    GPU2D_B->SetFramebuffer(&Framebuffer[0]);
+    int backbuf = FrontBuffer ? 0 : 1;
+    GPU2D_A->SetFramebuffer(Framebuffer[backbuf][1]);
+    GPU2D_B->SetFramebuffer(Framebuffer[backbuf][0]);
 }
 
 void Stop()
 {
-    memset(Framebuffer, 0, FBScreenStride*2*sizeof(u32));
+    memset(Framebuffer[0][0], 0, (256*192)<<(FBScale[0]*2));
+    memset(Framebuffer[0][1], 0, (256*192)<<(FBScale[1]*2));
+    memset(Framebuffer[1][0], 0, (256*192)<<(FBScale[0]*2));
+    memset(Framebuffer[1][1], 0, (256*192)<<(FBScale[1]*2));
 }
 
 void DoSavestate(Savestate* file)
@@ -215,13 +232,46 @@ void DoSavestate(Savestate* file)
     GPU3D::DoSavestate(file);
 }
 
-void SetFramebufferScale(int scale)
+void AssignFramebuffers()
+{
+    int backbuf = FrontBuffer ? 0 : 1;
+    if (NDS::PowerControl9 & (1<<15))
+    {
+        GPU2D_A->SetFramebuffer(Framebuffer[backbuf][0]);
+        GPU2D_B->SetFramebuffer(Framebuffer[backbuf][1]);
+    }
+    else
+    {
+        GPU2D_A->SetFramebuffer(Framebuffer[backbuf][1]);
+        GPU2D_B->SetFramebuffer(Framebuffer[backbuf][0]);
+    }
+}
+
+void SetFramebufferScale(int top, int bottom)
 {
-    FBScale = scale;
-    FBScreenStride = (256*scale) * (192*scale);
+    if (top != FBScale[0])
+    {
+        FBScale[0] = top;
 
-    if (Framebuffer) delete[] Framebuffer;
-    Framebuffer = new u32[FBScreenStride * 2];
+        int fbsize = (256 * 192) << (FBScale[0] * 2);
+        if (Framebuffer[0][0]) delete[] Framebuffer[0][0];
+        if (Framebuffer[1][0]) delete[] Framebuffer[1][0];
+        Framebuffer[0][0] = new u32[fbsize];
+        Framebuffer[1][0] = new u32[fbsize];
+    }
+
+    if (bottom != FBScale[1])
+    {
+        FBScale[1] = bottom;
+
+        int fbsize = (256 * 192) << (FBScale[1] * 2);
+        if (Framebuffer[0][1]) delete[] Framebuffer[0][1];
+        if (Framebuffer[1][1]) delete[] Framebuffer[1][1];
+        Framebuffer[0][1] = new u32[fbsize];
+        Framebuffer[1][1] = new u32[fbsize];
+    }
+
+    AssignFramebuffers();
 }
 
 
@@ -682,16 +732,7 @@ void SetPowerCnt(u32 val)
     GPU2D_B->SetEnabled(val & (1<<9));
     GPU3D::SetEnabled(val & (1<<3), val & (1<<2));
 
-    if (val & (1<<15))
-    {
-        GPU2D_A->SetFramebuffer(&Framebuffer[0]);
-        GPU2D_B->SetFramebuffer(&Framebuffer[FBScreenStride]);
-    }
-    else
-    {
-        GPU2D_A->SetFramebuffer(&Framebuffer[FBScreenStride]);
-        GPU2D_B->SetFramebuffer(&Framebuffer[0]);
-    }
+    AssignFramebuffers();
 }
 
 
@@ -762,6 +803,9 @@ void StartHBlank(u32 line)
 
 void FinishFrame(u32 lines)
 {
+    FrontBuffer = FrontBuffer ? 0 : 1;
+    AssignFramebuffers();
+
     TotalScanlines = lines;
 }
 
diff --git a/src/GPU.h b/src/GPU.h
index a430a32..2e47fc4 100644
--- a/src/GPU.h
+++ b/src/GPU.h
@@ -61,7 +61,8 @@ extern u32 VRAMMap_Texture[4];
 extern u32 VRAMMap_TexPal[8];
 extern u32 VRAMMap_ARM7[2];
 
-extern u32* Framebuffer;
+extern int FrontBuffer;
+extern u32* Framebuffer[2][2];
 
 extern GPU2D* GPU2D_A;
 extern GPU2D* GPU2D_B;
@@ -74,7 +75,7 @@ void Stop();
 
 void DoSavestate(Savestate* file);
 
-void SetFramebufferScale(int scale);
+void SetFramebufferScale(int top, int bottom);
 
 
 void MapVRAM_AB(u32 bank, u8 cnt);
diff --git a/src/libui_sdl/DlgVideoSettings.cpp b/src/libui_sdl/DlgVideoSettings.cpp
index ed33cb5..b6544ed 100644
--- a/src/libui_sdl/DlgVideoSettings.cpp
+++ b/src/libui_sdl/DlgVideoSettings.cpp
@@ -160,7 +160,7 @@ void Open()
 
         uiRadioButtons* rbApplyScalingTo = uiNewRadioButtons();
         uiRadioButtonsAppend(rbApplyScalingTo, "Both screens");
-        uiRadioButtonsAppend(rbApplyScalingTo, "Emphasized screen");
+        uiRadioButtonsAppend(rbApplyScalingTo, "Emphasized screen (see 'Screen sizing')");
         uiRadioButtonsAppend(rbApplyScalingTo, "Top screen");
         uiRadioButtonsAppend(rbApplyScalingTo, "Bottom screen");
         uiBoxAppend(in_ctrl, uiControl(rbApplyScalingTo), 0);
diff --git a/src/libui_sdl/main.cpp b/src/libui_sdl/main.cpp
index a8a5ceb..c8454ed 100644
--- a/src/libui_sdl/main.cpp
+++ b/src/libui_sdl/main.cpp
@@ -95,7 +95,8 @@ char PrevSRAMPath[1024]; // for savestate 'undo load'
 bool SavestateLoaded;
 
 bool ScreenDrawInited = false;
-uiDrawBitmap* ScreenBitmap = NULL;
+uiDrawBitmap* ScreenBitmap[2] = {NULL,NULL};
+SDL_mutex* ScreenMutex;
 u32* ScreenBuffer;
 
 int ScreenScale;
@@ -555,7 +556,7 @@ int EmuThreadFunc(void* burp)
                 }
             }
 
-            memcpy(ScreenBuffer, GPU::Framebuffer, (256*ScreenScale)*(384*ScreenScale)*4);
+            //memcpy(ScreenBuffer, GPU::Framebuffer, (256*ScreenScale)*(384*ScreenScale)*4);
             uiAreaQueueRedrawAll(MainDrawArea);
 
             // framerate limiter based off SDL2_gfx
@@ -636,24 +637,27 @@ void OnAreaDraw(uiAreaHandler* handler, uiArea* area, uiAreaDrawParams* params)
     if (!ScreenDrawInited)
     {
         ScreenDrawInited = true;
-        ScreenBitmap = uiDrawNewBitmap(params->Context, 256*ScreenScale, 384*ScreenScale);
+        ScreenBitmap[0] = uiDrawNewBitmap(params->Context, 256*ScreenScale, 384*ScreenScale);
+        ScreenBitmap[1] = uiDrawNewBitmap(params->Context, 256*ScreenScale, 384*ScreenScale);
     }
 
-    if (!ScreenBitmap) return;
+    if (!ScreenBitmap[0] || !ScreenBitmap[1]) return;
 
     uiRect top = {0, 0, 256*ScreenScale, 192*ScreenScale};
-    uiRect bot = {0, 192*ScreenScale, 256*ScreenScale, 192*ScreenScale};
+    uiRect bot = {0, 0, 256*ScreenScale, 192*ScreenScale};
 
-    if (ScreenBuffer) uiDrawBitmapUpdate(ScreenBitmap, ScreenBuffer);
+    int frontbuf = GPU::FrontBuffer;
+    uiDrawBitmapUpdate(ScreenBitmap[0], GPU::Framebuffer[frontbuf][0]);
+    uiDrawBitmapUpdate(ScreenBitmap[1], GPU::Framebuffer[frontbuf][1]);
 
     uiDrawSave(params->Context);
     uiDrawTransform(params->Context, &TopScreenTrans);
-    uiDrawBitmapDraw(params->Context, ScreenBitmap, &top, &TopScreenRect, Config::ScreenFilter==1);
+    uiDrawBitmapDraw(params->Context, ScreenBitmap[0], &top, &TopScreenRect, Config::ScreenFilter==1);
     uiDrawRestore(params->Context);
 
     uiDrawSave(params->Context);
     uiDrawTransform(params->Context, &BottomScreenTrans);
-    uiDrawBitmapDraw(params->Context, ScreenBitmap, &bot, &BottomScreenRect, Config::ScreenFilter==1);
+    uiDrawBitmapDraw(params->Context, ScreenBitmap[1], &bot, &BottomScreenRect, Config::ScreenFilter==1);
     uiDrawRestore(params->Context);
 }
 
@@ -1993,6 +1997,8 @@ int main(int argc, char** argv)
     uiMenuItemDisable(MenuItem_Reset);
     uiMenuItemDisable(MenuItem_Stop);
 
+    ScreenMutex = SDL_CreateMutex();
+
     uiAreaHandler areahandler;
     areahandler.Draw = OnAreaDraw;
     areahandler.MouseEvent = OnAreaMouseEvent;
@@ -2131,7 +2137,10 @@ int main(int argc, char** argv)
 
     Config::Save();
 
-    if (ScreenBitmap) uiDrawFreeBitmap(ScreenBitmap);
+    SDL_DestroyMutex(ScreenMutex);
+
+    if (ScreenBitmap[0]) uiDrawFreeBitmap(ScreenBitmap[0]);
+    if (ScreenBitmap[1]) uiDrawFreeBitmap(ScreenBitmap[1]);
 
     uiUninit();
     SDL_Quit();