Added frameskip.

Makefile.libretro

@@ -6,6 +6,7 @@ USE_CHEATS=1
 USE_TWEAKS=0
 USE_THREADED_RENDERER=0
 USE_MOTION_SENSOR=0
+USE_FRAME_SKIP=0
 HAVE_NEON=0
 
 CORE_DIR := .
@@ -228,7 +229,7 @@ else ifeq ($(platform), vita)
 	CXX = arm-vita-eabi-g++$(EXE_EXT)
 	AR = arm-vita-eabi-ar$(EXE_EXT)
 	PLATFORM_DEFINES := -DBRANCHLESS_GBA_GFX -DVITA
-	__FLAGS := -marm -mtune=cortex-a9 -mcpu=cortex-a9 -mfloat-abi=hard -mword-relocations
+	__FLAGS := -marm -mfpu=neon -mtune=cortex-a9 -mcpu=cortex-a9 -mfloat-abi=hard -mword-relocations
 	__FLAGS += -fno-optimize-sibling-calls -fno-strict-aliasing -fno-partial-inlining -fno-tree-vrp
 	__FLAGS += -ffast-math -fsingle-precision-constant -funroll-loops -ftracer
 
@@ -241,6 +242,7 @@ else ifeq ($(platform), vita)
 	USE_TWEAKS=1
 	USE_THREADED_RENDERER=1
 	USE_MOTION_SENSOR=1
+    USE_FRAME_SKIP=1
 	HAVE_NEON=1
 # Libxenon
 else ifeq ($(platform), xenon)
@@ -367,6 +369,11 @@ CFLAGS += -DUSE_MOTION_SENSOR
 CXXFLAGS += -DUSE_MOTION_SENSOR
 endif
 
+ifeq ($(USE_FRAME_SKIP), 1)
+CFLAGS += -DUSE_FRAME_SKIP
+CXXFLAGS += -DUSE_FRAME_SKIP
+endif
+
 LIBS :=
 
 %.o: %.cpp

libretro/libretro.cpp

@@ -142,6 +142,9 @@ void retro_set_environment(retro_environment_t cb)
 
    struct retro_variable variables[] = {
 	  { "vbanext_bios", "Use bios (if available); enabled|disabled" },
+#if USE_FRAME_SKIP
+	  { "vbanext_frameskip", "Frameskip; 0|1/3|1/2|1|2|3|4" },
+#endif
       { NULL, NULL },
    };
 
@@ -386,6 +389,27 @@ static void load_image_preferences (void)
    }
 }
 
+#if USE_FRAME_SKIP
+static int get_frameskip_code()
+{
+	struct retro_variable var;
+
+	var.key = "vbanext_frameskip";
+	var.value = NULL;
+
+	if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
+	{
+		if (strcmp(var.value, "1/3") == 0) return 0x13;
+		if (strcmp(var.value, "1/2") == 0) return 0x12;
+		if (strcmp(var.value, "1") == 0) return 0x1;
+		if (strcmp(var.value, "2") == 0) return 0x2;
+		if (strcmp(var.value, "3") == 0) return 0x3;
+		if (strcmp(var.value, "4") == 0) return 0x4;
+	}
+	return 0;
+}
+#endif
+
 static void gba_init(void)
 {
    cpuSaveType = 0;
@@ -435,6 +459,11 @@ static void gba_init(void)
    uint8_t * state_buf = (uint8_t*)malloc(2000000);
    serialize_size = CPUWriteState(state_buf, 2000000);
    free(state_buf);
+
+#if USE_FRAME_SKIP
+   SetFrameskip(get_frameskip_code());
+#endif
+
 }
 
 void retro_deinit(void)
@@ -484,15 +513,8 @@ static unsigned has_frame;
 
 static void update_variables(void)
 {
-#if 0
-   struct retro_variable var;
-
-   var.key = "vbam-next-undefined";
-   var.value = NULL;
-
-   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
-   {
-   }
+#if USE_FRAME_SKIP
+   SetFrameskip(get_frameskip_code());
 #endif
 }
 

src/gba.cpp

@@ -4,6 +4,7 @@
 #include <math.h>
 #include <stddef.h>
 #include <memalign.h>
+#include <time.h>
 
 #include "system.h"
 #include "globals.h"
@@ -51,6 +52,22 @@
 // Used in R_WIN_* to indicate whether color effects are enabled
 #define LayerMask_SFX  (1 << 5)
 
+#if USE_FRAME_SKIP
+
+int fs_count = 0;
+int fs_type = 0;
+int fs_type_a = 0;
+int fs_type_b = 0;
+bool fs_draw = false;
+
+void SetFrameskip(int code)
+{
+	fs_type = code;
+	fs_type_a = (0xF0 & fs_type) >> 4;
+	fs_type_b = 0xF & fs_type;
+}
+#endif
+
 typedef void (*renderfunc_t)(void);
 
 template<int renderer_idx>
@@ -11302,54 +11319,6 @@ static void threaded_renderer_loop(void* p) {
 	renderer_ctx.renderer_control = 0; //loop is terminated.
 }
 
-/*
-static void threaded_renderer_loop(void* p) {
-	int renderer_idx = reinterpret_cast<intptr_t>(p);
-	INIT_RENDERER_CONTEXT(renderer_idx);
-
-	renderfunc_t drawSprites = NULL;
-	renderfunc_t drawOBJWin = NULL;
-	renderfunc_t (*getRenderFunc)(int, int) = NULL;
-
-	switch(renderer_idx) {
-	case 0:
-		drawSprites = gfxDrawSprites<0>;
-		drawOBJWin = gfxDrawOBJWin<0>;
-		getRenderFunc = GetRenderFunc<0>;
-		break;
-	case 1:
-		drawSprites = gfxDrawSprites<1>;
-		drawOBJWin = gfxDrawOBJWin<1>;
-		getRenderFunc = GetRenderFunc<1>;
-		break;
-	case 2:
-		drawSprites = gfxDrawSprites<2>;
-		drawOBJWin = gfxDrawOBJWin<2>;
-		getRenderFunc = GetRenderFunc<2>;
-		break;
-	case 3:
-		drawSprites = gfxDrawSprites<3>;
-		drawOBJWin = gfxDrawOBJWin<3>;
-		getRenderFunc = GetRenderFunc<3>;
-		break;
-	default:
-		return;
-	}
-
-	while(renderer_ctx.renderer_control == 1) {
-		if(renderer_idx == 0) {
-			if(threaded_renderer_ready) {
-				threaded_renderer_ready = 0;
-				systemDrawScreen();
-			}
-		}
-		threaded_renderer_loop_impl();
-	}
-
-	renderer_ctx.renderer_control = 0; //loop is terminated.
-}
-*/
-
 static void fetchBackgroundOffset(int video_mode) {
 	//update gfxBG2X, gfxBG2Y, gfxBG3X, gfxBG3Y
 	switch(video_mode) {
@@ -12452,8 +12421,7 @@ void CPUUpdateRegister(uint32_t address, uint16_t value)
 }
 
 void CPUInit(const char *biosFileName, bool useBiosFile)
-{
-
+{	
 #ifdef MSB_FIRST
 	if(!cpuBiosSwapped)
    {
@@ -13065,6 +13033,20 @@ void CPULoop (void)
 #if !THREADED_RENDERER
 		            	systemDrawScreen();
 #endif
+
+#if USE_FRAME_SKIP
+						++fs_count;
+
+						if(fs_type_b == 0) {
+							fs_draw = true;
+						} else {
+							if(fs_type_a > 0) {
+								fs_draw = (fs_count % (fs_type_b + 1));
+							} else {
+								fs_draw = ((fs_count % (fs_type_b + 1)) == 0);
+							}
+						}
+#endif
 		            	framedone = true;
 		        	}
 
@@ -13073,23 +13055,29 @@ void CPULoop (void)
 				}
 				else
 				{
-
+#if USE_FRAME_SKIP
+					if(fs_draw) {
+#endif
 #if THREADED_RENDERER
-					postRender();
+						postRender();
 #else					
-					bool draw_objwin = (graphics.layerEnable & 0x9000) == 0x9000;
-					bool draw_sprites = R_DISPCNT_Screen_Display_OBJ;
+						bool draw_objwin = (graphics.layerEnable & 0x9000) == 0x9000;
+						bool draw_sprites = R_DISPCNT_Screen_Display_OBJ;
 
-					memset(RENDERER_LINE[Layer_OBJ], -1, 240 * sizeof(u32));	// erase all sprites
-					if(draw_sprites) gfxDrawSprites<0>();
+						memset(RENDERER_LINE[Layer_OBJ], -1, 240 * sizeof(u32));	// erase all sprites
+						if(draw_sprites) gfxDrawSprites<0>();
 
-					if(renderfunc_type == 2) {
-						memset(RENDERER_LINE[Layer_WIN_OBJ], -1, 240 * sizeof(u32));	// erase all OBJ Win 
-						if(draw_objwin) gfxDrawOBJWin<0>();
-					}
+						if(renderfunc_type == 2) {
+							memset(RENDERER_LINE[Layer_WIN_OBJ], -1, 240 * sizeof(u32));	// erase all OBJ Win 
+							if(draw_objwin) gfxDrawOBJWin<0>();
+						}
 
-					GetRenderFunc<0>(renderfunc_mode, renderfunc_type)();
+						GetRenderFunc<0>(renderfunc_mode, renderfunc_type)();
 #endif
+#if USE_FRAME_SKIP					
+					}
+#endif
+
 					// entering H-Blank
 					io_registers[REG_DISPSTAT] |= 2;
 					UPDATE_REG(0x04, io_registers[REG_DISPSTAT]);

src/gba.h

@@ -112,6 +112,9 @@ extern void CPUReset (void);
 extern void CPULoop(void);
 extern void UpdateJoypad(void);
 extern void CPUCheckDMA(int,int);
+#if USE_FRAME_SKIP
+extern void SetFrameskip(int);
+#endif
 
 #if THREADED_RENDERER
 extern void ThreadedRendererStart();