[nostalgia/core] Add ticksMs() function

src/nostalgia/core/config.hpp

@@ -11,5 +11,6 @@
 namespace nostalgia::core::config {
 
 constexpr auto GbaSpriteBufferLen = 128;
+constexpr auto GbaTimerBits = 64;
 
 }

src/nostalgia/core/core.hpp

@@ -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
@@ -20,4 +20,8 @@ namespace nostalgia::core {
 
 [[nodiscard]] ox::Error run(Context *ctx);
 
+// Returns the number of milliseconds that have passed since the start of the
+//  program.
+[[nodiscard]] uint64_t ticksMs();
+
 }

src/nostalgia/core/gba/CMakeLists.txt

@@ -6,7 +6,6 @@ if(NOSTALGIA_BUILD_TYPE STREQUAL "GBA")
 			core.cpp
 			gfx.cpp
 			irq.arm.cpp
-			irq.cpp
 			irq.s
 			media.cpp
 			panic.cpp

src/nostalgia/core/gba/addresses.hpp

@@ -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
@@ -26,6 +26,21 @@ using interrupt_handler = void (*)(void);
 #define REG_DISPSTAT *reinterpret_cast<volatile uint32_t*>(0x04000004)
 #define REG_VCOUNT   *reinterpret_cast<volatile uint32_t*>(0x04000006)
 
+/////////////////////////////////////////////////////////////////
+// Timers
+
+#define REG_TIMER0CTL *reinterpret_cast<volatile uint16_t*>(0x04000100)
+#define REG_TIMER0    *reinterpret_cast<volatile uint16_t*>(0x04000102)
+
+#define REG_TIMER1CTL *reinterpret_cast<volatile uint16_t*>(0x04000104)
+#define REG_TIMER1    *reinterpret_cast<volatile uint16_t*>(0x04000106)
+
+#define REG_TIMER2CTL *reinterpret_cast<volatile uint16_t*>(0x04000108)
+#define REG_TIMER2    *reinterpret_cast<volatile uint16_t*>(0x0400010a)
+
+#define REG_TIMER3CTL *reinterpret_cast<volatile uint16_t*>(0x0400010c)
+#define REG_TIMER3    *reinterpret_cast<volatile uint16_t*>(0x0400010e)
+
 /////////////////////////////////////////////////////////////////
 // background registers
 

src/nostalgia/core/gba/core.cpp

@@ -1,20 +1,45 @@
 /*
- * 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
  * 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 "irq.hpp"
 
+extern "C" void isr();
+
 namespace nostalgia::core {
 
+// Timer Consts
+constexpr auto NanoSecond = 1000000000;
+constexpr auto MilliSecond = 1000;
+constexpr int TicksMs59ns = (NanoSecond / MilliSecond) / 59.59;
+
+extern volatile ox::Uint<config::GbaTimerBits> g_timerMs;
+
+static void initIrq() {
+	REG_ISR = isr;
+	REG_IME = 1; // enable interrupts
+}
+
+static void initTimer() {
+	// make timer0 a ~1 millisecond timer
+	REG_TIMER0 = TicksMs59ns;
+	REG_TIMER0CTL = 0b11000011;
+	// enable interrupt for timer0
+	REG_IE |= Int_timer0;
+}
+
 ox::Error init(Context *ctx) {
 	oxReturnError(initGfx(ctx));
-	oxReturnError(initIrq(ctx));
+	initTimer();
+	initIrq();
 	return OxError(0);
 }
 
@@ -24,4 +49,8 @@ ox::Error run(Context*) {
 	return OxError(0);
 }
 
+uint64_t ticksMs() {
+	return g_timerMs;
+}
+
 }

src/nostalgia/core/gba/gfx.cpp

@@ -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
@@ -21,6 +21,10 @@ namespace nostalgia::core {
 
 constexpr auto GbaTileColumns = 32;
 
+constexpr uint16_t DispStat_irq_vblank = 1 << 3;
+constexpr uint16_t DispStat_irq_hblank = 1 << 4;
+constexpr uint16_t DispStat_irq_vcount = 1 << 5;
+
 struct GbaPaletteTarget {
 	static constexpr auto TypeName = NostalgiaPalette::TypeName;
 	static constexpr auto Fields = NostalgiaPalette::Fields;
@@ -87,6 +91,10 @@ ox::Error initGfx(Context*) {
 	/* Objects -----\||| */
 	/*              |||| */
 	REG_DISPCNT = 0x1101;
+	// tell display to trigger vblank interrupts
+	REG_DISPSTAT |= DispStat_irq_vblank;
+	// enable vblank interrupt
+	REG_IE |= Int_vblank;
 	return OxError(0);
 }
 
@@ -202,14 +210,14 @@ void setTile(Context*, int layer, int column, int row, uint8_t tile) {
 }
 
 void setSprite(unsigned idx, unsigned x, unsigned y, unsigned tileIdx) {
-	// block until g_spriteUpdates is less than buffer len
-	while (g_spriteUpdates >= config::GbaSpriteBufferLen);
 	GbaSpriteAttrUpdate oa;
 	oa.attr0 = static_cast<uint16_t>(y & ox::onMask<uint8_t>(7))
 	         | (static_cast<uint16_t>(1) << 10); // enable alpha
 	oa.attr1 = static_cast<uint16_t>(x) & ox::onMask<uint8_t>(8);
 	oa.attr2 = static_cast<uint16_t>(tileIdx & ox::onMask<uint16_t>(8));
 	oa.idx = idx;
+	// block until g_spriteUpdates is less than buffer len
+	while (g_spriteUpdates >= config::GbaSpriteBufferLen);
 	REG_IE &= ~Int_vblank; // disable vblank interrupt handler
 	g_spriteBuffer[g_spriteUpdates++] = oa;
 	REG_IE |= Int_vblank; // enable vblank interrupt handler

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

@@ -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
@@ -9,8 +9,6 @@
 // NOTE: this file is compiled as ARM and not THUMB, so don't but too much in
 // here
 
-#include <nostalgia/core/config.hpp>
-
 #include "addresses.hpp"
 #include "gfx.hpp"
 #include "irq.hpp"
@@ -20,6 +18,8 @@ namespace nostalgia::core {
 volatile uint16_t g_spriteUpdates = 0;
 GbaSpriteAttrUpdate g_spriteBuffer[config::GbaSpriteBufferLen];
 
+volatile uint32_t g_timerMs = 0;
+
 }
 
 using namespace nostalgia::core;
@@ -39,6 +39,7 @@ void nostalgia_core_isr_vblank() {
 }
 
 void nostalgia_core_isr_timer0() {
+	++g_timerMs;
 }
 
 void nostalgia_core_isr_timer1() {

src/nostalgia/core/gba/irq.cpp

@@ -1,29 +0,0 @@
-/*
- * Copyright 2016 - 2020 gtalent2@gmail.com
- *
- * 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 "irq.hpp"
-
-extern "C" void isr();
-
-namespace nostalgia::core {
-
-constexpr uint16_t DispStat_irq_vblank = 1 << 3;
-constexpr uint16_t DispStat_irq_hblank = 1 << 4;
-constexpr uint16_t DispStat_irq_vcount = 1 << 5;
-
-ox::Error initIrq(Context*) {
-	REG_ISR = isr;
-	// tell display to trigger vblank interrupts
-	REG_DISPSTAT |= DispStat_irq_vblank;
-	// tell proc which interrupts to handle
-	REG_IE |= Int_vblank;
-	REG_IME = 1;
-	return OxError(0);
-}
-
-}

src/nostalgia/core/gba/irq.hpp

@@ -1,15 +1,11 @@
 /*
- * 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
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-#include <nostalgia/core/context.hpp>
-
-#include "addresses.hpp"
-
 namespace nostalgia::core {
 
 constexpr uint16_t Int_vblank = 1 << 0;
@@ -29,6 +25,4 @@ constexpr uint16_t Int_dma5   = 1 << 13;
 constexpr uint16_t Int_input  = 1 << 14; // gamepad
 constexpr uint16_t Int_cart   = 1 << 15; // cartridge removed
 
-[[nodiscard]] ox::Error initIrq(Context *ctx);
-
 }

src/nostalgia/core/sdl/core.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
@@ -41,4 +41,8 @@ ox::Error run(Context *ctx) {
 	return OxError(0);
 }
 
+uint64_t ticksMs() {
+	return SDL_GetTicks();;
+}
+
 }