[nostalgia/core/gba] Fix event cycle and add to setter for event handler

src/nostalgia/core/config.hpp

@@ -8,9 +8,17 @@
 
 #pragma once
 
-namespace nostalgia::core::config {
+#include <ox/std/types.hpp>
+
+namespace nostalgia::core {
+
+namespace config {
 
 constexpr auto GbaSpriteBufferLen = 128;
-constexpr auto GbaTimerBits = 64;
+constexpr auto GbaEventLoopTimerBased = false;
+
+}
+
+using gba_timer_t = uint32_t;
 
 }

src/nostalgia/core/core.hpp

@@ -16,10 +16,16 @@
 
 namespace nostalgia::core {
 
+using event_handler = int(*)(void);
+
 [[nodiscard]] ox::Error init(Context *ctx);
 
 [[nodiscard]] ox::Error run(Context *ctx);
 
+// Sets event handler that sleeps for the time given in the return value. The
+// sleep time is a minimum of ~16 milliseconds.
+void setEventHandler(event_handler);
+
 // Returns the number of milliseconds that have passed since the start of the
 //  program.
 [[nodiscard]] uint64_t ticksMs();

src/nostalgia/core/gba/CMakeLists.txt

@@ -4,6 +4,7 @@ if(NOSTALGIA_BUILD_TYPE STREQUAL "GBA")
 	add_library(
 		NostalgiaCore-GBA
 			bios.s
+			core.arm.cpp
 			core.cpp
 			gfx.cpp
 			irq.arm.cpp
@@ -12,7 +13,7 @@ if(NOSTALGIA_BUILD_TYPE STREQUAL "GBA")
 			panic.cpp
 	)
 
-	set_source_files_properties(irq.arm.cpp PROPERTIES COMPILE_FLAGS -marm)
+	set_source_files_properties(core.arm.cpp irq.arm.cpp PROPERTIES COMPILE_FLAGS -marm)
 
 	target_link_libraries(
 		NostalgiaCore-GBA PUBLIC

src/nostalgia/core/gba/bios.hpp

@@ -8,14 +8,19 @@
 
 #pragma once
 
+// Functions for accessing BIOS calls
+
 extern "C" {
 
+// waits for any interrupt
 void nostalgia_core_halt();
 
 void nostalgia_core_stop();
 
-void nostalgia_core_wfi();
+// waits for interrupts specified in interSubs
+void nostalgia_core_intrwait(unsigned discardExistingIntrs, unsigned intrSubs);
 
-void nostalgia_core_vblankwfi();
+// waits for vblank interrupt
+void nostalgia_core_vblankintrwait();
 
 }

src/nostalgia/core/gba/bios.s

@@ -1,5 +1,5 @@
 //
-// Copyright 2016 - 2020 gtalent2@gmail.com
+// Copyright 2016 - 2020 gary@drinkingtea.net
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -22,15 +22,15 @@ nostalgia_core_stop:
 	swi 3
 	bx lr
 
-.global nostalgia_core_wfi
-.type nostalgia_core_wfi, %function
-nostalgia_core_wfi:
+.global nostalgia_core_intrwait
+.type nostalgia_core_intrwait, %function
+nostalgia_core_intrwait:
 	swi 4
 	bx lr
 
-.global nostalgia_core_vblankwfi
-.type nostalgia_core_vblankwfi, %function
-nostalgia_core_vblankwfi:
+.global nostalgia_core_vblankintrwait
+.type nostalgia_core_vblankintrwait, %function
+nostalgia_core_vblankintrwait:
 	swi 5
 	bx lr
 

src/nostalgia/core/gba/core.arm.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2016 - 2020 gary@drinkingtea.net
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <nostalgia/core/config.hpp>
+#include <nostalgia/core/core.hpp>
+
+#include "addresses.hpp"
+#include "bios.hpp"
+#include "irq.hpp"
+
+extern "C" void isr();
+
+namespace nostalgia::core {
+
+extern volatile gba_timer_t g_timerMs;
+gba_timer_t g_wakeupTime;
+event_handler g_eventHandler = nullptr;
+
+ox::Error run(Context*) {
+	g_wakeupTime = 0;
+	while (1) {
+		if (g_wakeupTime <= g_timerMs && g_eventHandler) {
+			auto sleepTime = g_eventHandler();
+			if (sleepTime >= 0) {
+				g_wakeupTime = g_timerMs + static_cast<unsigned>(sleepTime);
+			} else {
+				g_wakeupTime = ~gba_timer_t(0);
+			}
+		}
+		if constexpr(config::GbaEventLoopTimerBased) {
+			// wait for timer interrupt
+			nostalgia_core_intrwait(0, Int_timer0 | Int_timer1 | Int_timer2 | Int_timer3);
+		} else {
+			nostalgia_core_vblankintrwait();
+		}
+	}
+	return OxError(0);
+}
+
+}

src/nostalgia/core/gba/core.cpp

@@ -18,11 +18,13 @@ extern "C" void isr();
 namespace nostalgia::core {
 
 // Timer Consts
-constexpr auto NanoSecond = 1000000000;
-constexpr auto MilliSecond = 1000;
+constexpr int NanoSecond = 1000000000;
+constexpr int MilliSecond = 1000;
 constexpr int TicksMs59ns = 65535 - (NanoSecond / MilliSecond) / 59.59;
 
-extern volatile ox::Uint<config::GbaTimerBits> g_timerMs;
+extern event_handler g_eventHandler;
+
+extern volatile gba_timer_t g_timerMs;
 
 static void initIrq() {
 	REG_ISR = isr;
@@ -44,11 +46,8 @@ ox::Error init(Context *ctx) {
 	return OxError(0);
 }
 
-ox::Error run(Context*) {
-	while (1) {
-		nostalgia_core_vblankwfi();
-	}
-	return OxError(0);
+void setEventHandler(event_handler h) {
+	g_eventHandler = h;
 }
 
 uint64_t ticksMs() {

src/nostalgia/core/gba/gfx.cpp

@@ -225,11 +225,18 @@ void setSprite(unsigned idx, unsigned x, unsigned y, unsigned tileIdx) {
 	oa.idx = idx;
 	// block until g_spriteUpdates is less than buffer len
 	if (g_spriteUpdates >= config::GbaSpriteBufferLen) {
-		nostalgia_core_vblankwfi();
+		nostalgia_core_vblankintrwait();
 	}
+	if constexpr(config::GbaEventLoopTimerBased) {
 		REG_IE &= ~Int_vblank; // disable vblank interrupt handler
 		g_spriteBuffer[g_spriteUpdates++] = oa;
 		REG_IE |= Int_vblank; // enable vblank interrupt handler
+	} else {
+		auto ie = REG_IE; // disable vblank interrupt handler
+		REG_IE &= ~Int_vblank; // disable vblank interrupt handler
+		g_spriteBuffer[g_spriteUpdates++] = oa;
+		REG_IE = ie; // enable vblank interrupt handler
+	}
 }
 
 }

src/nostalgia/core/gba/irq.arm.cpp

@@ -18,7 +18,7 @@ namespace nostalgia::core {
 volatile uint16_t g_spriteUpdates = 0;
 GbaSpriteAttrUpdate g_spriteBuffer[config::GbaSpriteBufferLen];
 
-volatile uint32_t g_timerMs = 0;
+volatile gba_timer_t g_timerMs = 0;
 
 }
 
@@ -36,6 +36,10 @@ void nostalgia_core_isr_vblank() {
 		MEM_OAM[oa.idx] = *reinterpret_cast<uint64_t*>(&oa);
 	}
 	g_spriteUpdates = 0;
+	if constexpr(config::GbaEventLoopTimerBased) {
+		// disable vblank interrupt until it is needed again
+		REG_IE &= ~Int_vblank;
+	}
 }
 
 void nostalgia_core_isr_timer0() {

src/nostalgia/core/gba/irq.hpp

@@ -26,9 +26,3 @@ constexpr uint16_t Int_input  = 1 << 14; // gamepad
 constexpr uint16_t Int_cart   = 1 << 15; // cartridge removed
 
 }
-
-extern "C" {
-
-void nostalgia_core_wfi();
-
-}

src/nostalgia/core/gba/panic.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2019 gtalent2@gmail.com
+ * Copyright 2016 - 2020 gary@drinkingtea.net
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -31,10 +31,9 @@ void panic(const char*, int, const char *msg, ox::Error err) {
 	puts(nullptr, 32 + 2,  6, msg);
 	puts(nullptr, 32 + 2,  8, serr.c_str());
 	puts(nullptr, 32 + 1, 15, "PLEASE RESTART THE SYSTEM");
-	// disable interrupts and wait for interrupt, halt and stop seem to have
-	// issues in mGBA
-	REG_IME = 0;
-	nostalgia_core_wfi();
+	// disable all interrupt handling and IntrWait on no interrupts
+	REG_IE = 0;
+	nostalgia_core_intrwait(0, 0);
 }
 
 }

src/nostalgia/core/sdl/core.cpp

@@ -9,9 +9,12 @@
 #include <SDL.h>
 
 #include <nostalgia/core/gfx.hpp>
+#include <nostalgia/core/core.hpp>
 
 namespace nostalgia::core {
 
+static event_handler g_eventHandler = nullptr;
+
 void draw(Context *ctx);
 
 ox::Error init(Context *ctx) {
@@ -41,6 +44,10 @@ ox::Error run(Context *ctx) {
 	return OxError(0);
 }
 
+void setEventHandler(event_handler h) {
+	g_eventHandler = h;
+}
+
 uint64_t ticksMs() {
 	return SDL_GetTicks();;
 }