From 047544a5af9100ec269e9222213385bc7794f619 Mon Sep 17 00:00:00 2001
From: Nicholas Tay <nick@windblume.net>
Date: Sat, 7 May 2022 23:26:27 +1000
Subject: 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.
---
 platform/platform.h | 10 +++++++
 platform/win32.c    | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 platform/platform.h
 create mode 100644 platform/win32.c

(limited to 'platform')

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
-- 
cgit