Reorganise C structure

This is a big C reorg to serve two main purposes:
- Be more consistent with C and GBDK patterns
- Separate modules and logic where possible. It will allow unit testing (next PR) and enable more contained enhancements (e.g. new screens, new synth concepts) and encourage small bug fixes

Changes:
- Refactors C to use .h patterns
- Splits code into modules: io, synth, screen. Consolidates global variables, easier to test and clearer which functionality owns which variables
- Converts ASM playNote* and update* for Pu1, Pu2, Wav, Noi into C functions
  - Most are pretty comparable in speed, so this shouldn't be a big perf regression (stats in comments above methods)
- Use structs for a bunch of arrays to improve readability (pointer to struct members is similar to array access (still more room for improvement)
- Use GBDK global vars for readability (e.g. rAUD3LOW, _AUDWAVERAM, rAUDENA, etc)

.editorconfig

@@ -0,0 +1,20 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[Makefile]
+indent_style = tab
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true

.vscode/c_cpp_properties.json

@@ -2,11 +2,12 @@
   "configurations": [
     {
       "name": "Mac",
-      "includePath": ["${workspaceFolder}/**"],
+      "includePath": ["${workspaceFolder}/gbdk/include"],
       "defines": ["__TARGET_gb=1", "__PORT_sm83=1"],
-      "compilerPath": "",
+      "compilerPath": "${workspaceFolder}/gbdk/bin/lcc",
       "cStandard": "c11",
-      "intelliSenseMode": "${default}"
+      "intelliSenseMode": "${default}",
+      "browse": { "limitSymbolsToIncludedHeaders": true }
     }
   ],
   "version": 4

.vscode/tasks.json

@@ -28,6 +28,15 @@
       },
       "problemMatcher": []
     },
+    {
+      "label": "make-clean",
+      "type": "shell",
+      "command": "make clean",
+      "options": {
+        "cwd": "Source/"
+      },
+      "problemMatcher": []
+    },
     {
       "label": "install",
       "detail": "Installs the rom onto a cartridge using ems-flasher (bank 2)",

Source/Makefile

@@ -1,16 +1,18 @@
-# If you move this project you can change the directory 
+# If you move this project you can change the directory
 # to match your GBDK root directory (ex: GBDK_HOME = "C:/GBDK/"
 ifndef GBDK_HOME
-	GBDK_HOME = ../gbdk
+  GBDK_HOME = ../gbdk
 endif
 
 PROJECTNAME = mGB
 
-LCC = $(GBDK_HOME)/bin/lcc 
+MAKEFLAGS += --no-builtin-rules
+
+LCC = $(GBDK_HOME)/bin/lcc
 
 LCCFLAGS += -msm83:gb # GB/GBC
 # LCCFLAGS += -v # verbose
-# LCCFLAGS += -autobank 
+# LCCFLAGS += -autobank
 
 ifdef DEBUG
 LCCFLAGS += -debug -v
@@ -44,28 +46,59 @@ endif
 # LCCFLAGS += -Wm-yS # Convert .noi file named like input file to .sym
 LCCFLAGS += -Wm-yc # GBC compatible
 LCCFLAGS += -Wm-yn"$(PROJECTNAME)" # cartridge name
-LCCFLAGS += -Wm-yt3 # MBC type = ROM+MBC1+RAM+BATT 
+LCCFLAGS += -Wm-yt3 # MBC type = ROM+MBC1+RAM+BATT
 LCCFLAGS += -Wm-ya1 # number of ram banks: -ya 1
 
+LCCFLAGS += -Wf-MMD
+
+OBJDIR      = obj
+OUTDIR      = out
+
+
+BIN	        = $(OUTDIR)/$(PROJECTNAME).gb
+
+MKDIRS      = $(OUTDIR) $(OBJDIR)/io $(OBJDIR)/screen $(OBJDIR)/synth $(OBJDIR)/io/sram
+
+C_SOURCES    = $(wildcard *.c)
+C_SOURCES    += $(wildcard **/*.c)
+
+SRAM_BANK0  = $(wildcard io/sram/*.b0.c)
+
+ASM_SOURCES  = $(wildcard **/*.s)
+
+
+OBJS        = $(C_SOURCES:%.c=$(OBJDIR)/%.o)
+OBJS        += $(ASM_SOURCES:%.s=$(OBJDIR)/%.o)
+OBJS        += $(SRAM_BANK0:%.b0.c=$(OBJDIR)/%.b0.o)
+
+
+# Builds all targets sequentially
+all: $(BIN)
+
+# Dependencies - for better incremental builds
+DEPS = $(OBJS:%.o=%.d)
+-include $(DEPS)
+
+# sram banks
+$(OBJDIR)/%.b0.o: %.b0.c
+	$(LCC) $(LCCFLAGS) -Wf-ba0 -c -o $@ $<
 
-OBJ=obj
-OUT=out
+# Compile .c files to .o object files
+$(OBJDIR)/%.o: %.c
+	$(LCC) $(LCCFLAGS) -c -o $@ $<
 
-build:
-	mkdir -p $(OBJ)
-	mkdir -p $(OUT)
-
-	# mostly so you can see the .asm
-	$(LCC) $(LCCFLAGS) -c -o $(OBJ)/mGB.rel mGB.c
+# Compile .s assembly files to .o object files
+$(OBJDIR)/%.o: %.s
+	$(LCC) $(LCCFLAGS) -c -o $@ $<
 
-  # SRAM bank 0
-	$(LCC) $(LCCFLAGS) -Wf-ba0 -c -o $(OBJ)/mgb_save.rel mgb_save.c
-	$(LCC) $(LCCFLAGS) -o $(OUT)/$(PROJECTNAME).gb $(OBJ)/mGB.rel $(OBJ)/mgb_save.rel *.s
+# Link the compiled object files into a .gb ROM file
+$(BIN):	makedirs $(OBJS)
+	$(LCC) $(LCCFLAGS) -o $(BIN) $(OBJS)
 
-compile.bat: Makefile
-	@echo "REM Automatically generated from Makefile" > compile.bat
-	@make -sn | sed y/\\//\\\\/ | sed s/mkdir\ \-p/mkdir/ | grep -v make >> compile.bat
+.PHONY: makedirs
+makedirs:
+	mkdir -p $(MKDIRS)
 
+.PHONY: clean
 clean:
-	rm -rf $(OBJ)
-	rm -rf $(OUT)
+	rm -rf $(OBJDIR) $(OUTDIR)

Source/mGBMidiFunctions.c → Source/io/midi.c

@@ -1,15 +1,12 @@
-#include "mGB.h"
+#include "midi.h"
+#include "../mGB.h"
+#include "midi_asm.h"
+#include "serial.h"
 
-#define MIDI_STATUS_BIT 0x80
-#define MIDI_STATUS_NOTE_ON 0x09
-#define MIDI_STATUS_NOTE_OFF 0x08
-#define MIDI_STATUS_AT 0x0A
-#define MIDI_STATUS_CC 0x0B
-#define MIDI_STATUS_PC 0x0C
-#define MIDI_STATUS_AT_MONO 0x0D
-#define MIDI_STATUS_PB 0x0E
-
-#define MIDI_STATUS_SYSTEM 0xF0
+uint8_t statusByte;
+uint8_t addressByte;
+uint8_t valueByte;
+uint8_t capturedAddress;
 
 void updateMidiBuffer(void) {
   if (serialBufferReadPosition == serialBufferPosition) {
@@ -18,7 +15,7 @@ void updateMidiBuffer(void) {
 
   serialBufferReadPosition++; // unsigned overflow from 255 -> 0 is automatic.
 
-  UBYTE byte = serialBuffer[serialBufferReadPosition];
+  uint8_t byte = serialBuffer[serialBufferReadPosition];
 
   // STATUS BYTE
   if (byte & MIDI_STATUS_BIT) {
@@ -61,4 +58,4 @@ void updateMidiBuffer(void) {
     asmEventMidiPC();
     break;
   }
-}
+}

Source/io/midi.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <gbdk/platform.h>
+
+#define MIDI_STATUS_BIT 0x80
+#define MIDI_STATUS_NOTE_ON 0x09
+#define MIDI_STATUS_NOTE_OFF 0x08
+#define MIDI_STATUS_AT 0x0A
+#define MIDI_STATUS_CC 0x0B
+#define MIDI_STATUS_PC 0x0C
+#define MIDI_STATUS_AT_MONO 0x0D
+#define MIDI_STATUS_PB 0x0E
+
+#define MIDI_STATUS_SYSTEM 0xF0
+
+// MIDI status
+extern uint8_t statusByte;
+// MIDI address (e.g. note/CC control)
+extern uint8_t addressByte;
+// MIDI value (e.g. velocity/value)
+extern uint8_t valueByte;
+extern uint8_t capturedAddress;
+
+void updateMidiBuffer(void);

Source/io/midi_asm.h

@@ -0,0 +1,7 @@
+#pragma once
+
+extern void asmEventMidiPB(void);
+extern void asmEventMidiCC(void);
+extern void asmEventMidiNote(void);
+extern void asmEventMidiNoteOff(void);
+extern void asmEventMidiPC(void);

Source/mGBASMMidiFunctions.s → Source/io/midi_asm.s

@@ -1,4 +1,27 @@
-.module mGBASMMidiFunctions
+  .module midi_asm
+	.optsdcc -msm83
+
+  .globl _addressByte
+  .globl _dataSet
+  .globl _noiEnv
+  .globl _noiSus
+  .globl _parameterLock
+  .globl _pbRange
+  .globl _pbWheelIn
+  .globl _playNoteNoi
+  .globl _playNotePoly
+  .globl _playNotePu1
+  .globl _playNotePu2
+  .globl _playNoteWav
+  .globl _pu1State
+  .globl _pu2State
+  .globl _statusByte
+  .globl _valueByte
+  .globl _vibratoDepth
+  .globl _vibratoSpeed
+  .globl _wavDataOffset
+  .globl _wavSus
+  .globl _wavSweepSpeed
 
 _popReturn$::
 ret
@@ -13,15 +36,15 @@ _asmEventMidiNote::
 	ld  a,(#_statusByte)
 	AND	#0x0F
 	cp	#0x00
-		jp z,_asmPlayNotePu1;
+		jp z,_playNotePu1
 	cp	#0x01
-		jp z,_asmPlayNotePu2$;
+		jp z,_playNotePu2
 	cp	#0x02
-		jp z,_asmPlayNoteWav$;
+		jp z,_playNoteWav
 	cp	#0x03
-		jp z,_asmPlayNoteNoi$;
+		jp z,_playNoteNoi
 	cp	#0x04
-		jp z,_asmPlayNotePoly$;
+		jp z,_playNotePoly
 ret
 
 _asmEventMidiCC::
@@ -232,7 +255,7 @@ _asmPu1Env$::
 	RRCA
 	AND #0x0F
 
-	ld	hl,#_pu1Env
+	ld	hl,#_pu1State + 0
 	ld	(hl),A
 
 	ld	de,#_dataSet + 2
@@ -369,14 +392,14 @@ _asmPu1SusOn$::
 	ld	A,#0x01
 	ld	de,#_dataSet + 5
     ld	(de),A
-	ld	hl,#_pu1Sus
+	ld	hl,#_pu1State + 1
     ld	(hl),A
 ret
 _asmPu1SusOff$::
 	ld	A,#0x00
 	ld	de,#_dataSet + 5
     ld	(de),A
-	ld	hl,#_pu1Sus
+	ld	hl,#_pu1State + 1
     ld	(hl),A
 
 	ld	hl,#_noteStatus + 0
@@ -393,7 +416,7 @@ ret
 _asmPu1Nf$::
 	ld	A,#0x00
 	ld (#0xFF12),A
-	ld	hl,#_pu1Sus
+	ld	hl,#_pu1State + 1
     ld	(hl),A
 	ld	de,#_dataSet + 5
     ld	(de),A
@@ -463,7 +486,7 @@ _asmPu2Env$::
 	RRCA
 	AND #0x0F
 
-	ld	hl,#_pu2Env
+	ld	hl,#_pu2State + 0
 	ld	(hl),A
 
 	ld	de,#_dataSet + 9
@@ -583,14 +606,14 @@ _asmPu2SusOn$::
 	ld	A,#0x01
 	ld	de,#_dataSet + 11
     ld	(de),A
-	ld	hl,#_pu2Sus
+	ld	hl,#_pu2State + 1
     ld	(hl),A
 ret
 _asmPu2SusOff$::
 	ld	A,#0x00
 	ld	de,#_dataSet + 11
     ld	(de),A
-	ld	hl,#_pu2Sus
+	ld	hl,#_pu2State + 1
     ld	(hl),A
 
 	ld	hl,#_noteStatus + 5
@@ -607,7 +630,7 @@ ret
 _asmPu2Nf$::
 	ld	A,#0x00
 	ld (#0xFF17),A
-	ld	hl,#_pu2Sus
+	ld	hl,#_pu2State + 1
     ld	(hl),A
 	ld	de,#_dataSet + 11
     ld	(de),A

Source/serial.c → Source/io/serial.c

@@ -1,6 +1,11 @@
-#include "mGB.h"
+#include "serial.h"
+#include "../mGB.h"
 #include <gb/isr.h>
 
+uint8_t serialBuffer[256];
+uint8_t serialBufferPosition;
+uint8_t serialBufferReadPosition;
+
 void serial_isr(void) CRITICAL INTERRUPT {
   serialBufferPosition++; // unsigned overflow from 255 -> 0 is automatic.
   serialBuffer[serialBufferPosition] = rSB;
@@ -14,4 +19,4 @@ void serial_isr(void) CRITICAL INTERRUPT {
   systemIdle = 0;
 }
 
-ISR_VECTOR(VECTOR_SERIAL, serial_isr)
+ISR_VECTOR(VECTOR_SERIAL, serial_isr)

Source/io/serial.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <gbdk/platform.h>
+
+extern uint8_t serialBuffer[256];
+extern uint8_t serialBufferPosition;
+extern uint8_t serialBufferReadPosition;