Split out platform-specific code for Windows

Not sure if I'm really doing it in the best way possible. Feels a bit
weird that some place assumes the existence of other functions.

4 files changed, 116 insertions, 75 deletions

diff --git a/Makefile b/Makefile
index c2a94a6..bd016b7 100644
--- a/Makefile
+++ b/Makefile
@@ -5,14 +5,23 @@ BOARDS = mxblue quack
 
 CC = gcc
 CFLAGS += -std=c99 -Wall -Wextra -Wshadow -Werror -pedantic
-LDLIBS = -lWinmm
 
 BOARD_FILES = $(addsuffix /board.h,$(addprefix board/,$(BOARDS)))
 
+ifeq ($(OS),Windows_NT)
+    LDLIBS = -lWinmm
+    PLATFORM = win32
+else
+    UNAME_S := $(shell uname)
+    ifeq ($(UNAME_S),Linux)
+        PLATFORM = linux
+    endif
+endif
+
 default: $(NAME)
 
-$(NAME): $(NAME).c $(BOARD_FILES) board/boards.h
-	$(CC) $(CFLAGS) $(NAME).c $(LDLIBS) -o $(NAME)
+$(NAME): $(NAME).c platform/$(PLATFORM).c $(BOARD_FILES) board/boards.h
+	$(CC) $(CFLAGS) $(NAME).c platform/$(PLATFORM).c $(LDLIBS) -o $(NAME)
 
 board/boards.h:
 	printf "#ifndef BOARD_DEFAULTS_H\n#define BOARD_DEFAULTS_H\n\n" > board/boards.h
diff --git a/clak.c b/clak.c
index 99b1482..eace40d 100644
--- a/clak.c
+++ b/clak.c
@@ -1,15 +1,16 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
-#include <signal.h>
-
-#include <windows.h>
+#include <stdbool.h>
+#include <stdlib.h>
 
 #define VOLUME 0.15
 
 #include "board/boards.h"
 #define BOARD(str, buf) { .name = str, .wav = buf },
 
+#include "platform/platform.h"
+
 typedef struct {
 	char *name;
 	unsigned char* wav;
@@ -20,16 +21,7 @@ Board boards[] = {
 };
 int const boards_n = sizeof(boards) / sizeof(boards[0]);
 
-void sound_init(void)
-{
-	DWORD channel_volume = VOLUME * 0xFFFF;
-	waveOutSetVolume(NULL, (channel_volume << 16) | channel_volume);
-}
-
-void sound_play(unsigned char *buffer)
-{
-	PlaySound((const char *) buffer, NULL, SND_MEMORY | SND_ASYNC | SND_NODEFAULT);
-}
+Board *board = NULL;
 
 Board *get_board(char *board_name)
 {
@@ -40,15 +32,6 @@ Board *get_board(char *board_name)
 	return NULL;
 }
 
-HHOOK keyboard_hook_windows;
-
-void keyboard_unhook(void)
-{
-	fprintf(stderr, "Cleaning up keyboard hook...\n");
-	if (!UnhookWindowsHookEx(keyboard_hook_windows))
-		printf("WARN: Windows keyboard hook could not be cleaned up! Error code: %lu\n", GetLastError());
-}
-
 void do_exit(int code)
 {
 	keyboard_unhook();
@@ -57,8 +40,6 @@ void do_exit(int code)
 }
 void on_clean_exit(void) { do_exit(0); }
 
-Board *board = NULL;
-
 void keyboard_on_down(void)
 {
 	if (board == NULL)
@@ -72,43 +53,6 @@ void keyboard_on_up(void)
 	// 	return;
 }
 
-/* https://docs.microsoft.com/en-us/previous-versions/windows/desktop/legacy/ms644985(v=vs.85) */
-LRESULT CALLBACK keyboard_windows_callback(int nCode, WPARAM wParam, LPARAM lParam)
-{
-	/* Needed to prevent repeat fires */
-	static DWORD prev_vk = 0;
-
-	/* Do not handle unless nCode >= 0, pass to next hook right away */
-	if (nCode >= 0) {
-		BOOL down = wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN;
-		KBDLLHOOKSTRUCT *hook_struct = (KBDLLHOOKSTRUCT *) lParam;
-		DWORD vk = hook_struct->vkCode;
-		if (down && vk != prev_vk) {
-			keyboard_on_down();
-			prev_vk = vk;
-		} else {
-			keyboard_on_up();
-			/* Seems like repeat strokes are 0x0 or 0x1, and 'real' ones have 0x80 flag??
-			   Not really sure how to handle this one, can't find many docs...
-			   Saw this though: https://github.com/pyglet/pyglet/blob/838d004d68fcc5c3ce83b733e3d088fad0643859/pyglet/window/win32/__init__.py#L794= */
-			if (hook_struct->flags & 0x80)
-				prev_vk = 0;
-		}
-	}
-
-	return CallNextHookEx(NULL, nCode, wParam, lParam);
-}
-
-void keyboard_hook(void)
-{
-	fprintf(stderr, "Setting up keyboard hook...\n");
-	keyboard_hook_windows = SetWindowsHookEx(WH_KEYBOARD_LL, keyboard_windows_callback, NULL, 0);
-	if (keyboard_hook_windows == NULL) {
-		printf("ERROR: Could not set up Windows keyboard hook.\n");
-		do_exit(1);
-	}
-}
-
 int main(int argc, char **argv)
 {
 	if (argc < 2 || (board = get_board(argv[1])) == NULL) {
@@ -120,20 +64,18 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	sound_init();
-	keyboard_hook();
+	if (!sound_init(VOLUME)) {
+		printf("ERROR: Could not initialise sound system.\n");
+		return 1;
+	}
+	if (!keyboard_hook()) {
+		printf("ERROR: Could not set up keyboard hooks.\n");
+		return 1;
+	}
 	atexit(on_clean_exit);
 	fprintf(stderr, "Hooks set up, welcome to Clak!\n");
 
-	MSG msg;
-	BOOL status;
-	while ((status = GetMessage(&msg, NULL, 0, 0))) {
-		if (status == -1) {
-			// error case
-			printf("ERROR: Windows error, code %lu\n", GetLastError());
-			exit(1);
-		}
-	}
+	enter_idle();
 
 	return 0;
 }
\ No newline at end of file
diff --git a/platform/platform.h b/platform/platform.h
new file mode 100644
index 0000000..da1efa6
--- /dev/null
+++ b/platform/platform.h
@@ -0,0 +1,10 @@
+#ifndef CLAK_PLATFORM_H_
+#define CLAK_PLATFORM_H_
+
+bool sound_init(float volume);
+void sound_play(unsigned char *buffer);
+void keyboard_unhook(void);
+bool keyboard_hook(void);
+void enter_idle(void);
+
+#endif /* CLAK_PLATFORM_H_ */
\ No newline at end of file
diff --git a/platform/win32.c b/platform/win32.c
new file mode 100644
index 0000000..90cd37c
--- /dev/null
+++ b/platform/win32.c
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <windows.h>
+
+/* Required callbacks */
+extern void keyboard_on_down(void);
+extern void keyboard_on_up(void);
+
+static HHOOK keyboard_hook_windows;
+
+bool sound_init(float volume)
+{
+	DWORD channel_volume = volume * 0xFFFF;
+	if (waveOutSetVolume(NULL, (channel_volume << 16) | channel_volume) != MMSYSERR_NOERROR)
+		return false;
+	return true;
+}
+
+void sound_play(unsigned char *buffer)
+{
+	PlaySound((const char *) buffer, NULL, SND_MEMORY | SND_ASYNC | SND_NODEFAULT);
+}
+
+/* https://docs.microsoft.com/en-us/previous-versions/windows/desktop/legacy/ms644985(v=vs.85) */
+static LRESULT CALLBACK keyboard_windows_callback(int nCode, WPARAM wParam, LPARAM lParam)
+{
+	/* Needed to prevent repeat fires */
+	static DWORD prev_vk = 0;
+
+	/* Do not handle unless nCode >= 0, pass to next hook right away */
+	if (nCode >= 0) {
+		BOOL down = wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN;
+		KBDLLHOOKSTRUCT *hook_struct = (KBDLLHOOKSTRUCT *) lParam;
+		DWORD vk = hook_struct->vkCode;
+		if (down && vk != prev_vk) {
+			keyboard_on_down();
+			prev_vk = vk;
+		} else {
+			keyboard_on_up();
+			/* Seems like repeat strokes are 0x0 or 0x1, and 'real' ones have 0x80 flag??
+			   Not really sure how to handle this one, can't find many docs...
+			   Saw this though: https://github.com/pyglet/pyglet/blob/838d004d68fcc5c3ce83b733e3d088fad0643859/pyglet/window/win32/__init__.py#L794= */
+			if (hook_struct->flags & 0x80)
+				prev_vk = 0;
+		}
+	}
+
+	return CallNextHookEx(NULL, nCode, wParam, lParam);
+}
+
+bool keyboard_hook(void)
+{
+	fprintf(stderr, "Setting up keyboard hook...\n");
+	keyboard_hook_windows = SetWindowsHookEx(WH_KEYBOARD_LL, keyboard_windows_callback, NULL, 0);
+	if (keyboard_hook_windows == NULL) {
+		return false;
+	}
+	return true;
+}
+
+void keyboard_unhook(void)
+{
+	fprintf(stderr, "Cleaning up keyboard hook...\n");
+	if (!UnhookWindowsHookEx(keyboard_hook_windows))
+		printf("WARN: Windows keyboard hook could not be cleaned up! Error code: %lu\n", GetLastError());
+}
+
+void enter_idle(void)
+{
+	MSG msg;
+	BOOL status;
+	while ((status = GetMessage(&msg, NULL, 0, 0))) {
+		if (status == -1) {
+			// error case
+			printf("ERROR: Windows error, code %lu\n", GetLastError());
+			keyboard_unhook();
+			exit(1);
+		}
+	}
+}
\ No newline at end of file