Adding start to program RAW_X11

Makefile

@@ -25,6 +25,9 @@ sdl3: LDFLAGS+=$(shell pkg-config ${_PKG_STATIC} --libs sdl3)
 rl: CFLAGS+=$(shell pkg-config ${_PKG_STATIC} --cflags raylib)
 rl: LDFLAGS+=$(shell pkg-config ${_PKG_STATIC} --libs raylib)
 
+raw_x11: CFLAGS+=$(shell pkg-config ${_PKG_STATIC} --cflags x11)
+raw_x11: LDFLAGS+=$(shell pkg-config ${_PKG_STATIC} --libs x11)
+
 all: ${BIN}
 
 ${BIN}: %: src/%.o

src/raw_x11.c

@@ -0,0 +1,118 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xos.h>
+
+struct app {
+	Display *dis;
+	int32_t screen;
+	Window root_win;
+	GC gc;
+	struct {
+		Window it;
+		struct {
+			uint32_t w;
+			uint32_t h;
+		} size;
+		struct {
+			int32_t x;
+			int32_t y;
+		} pos;
+	} win;
+	struct {
+		uint64_t black;
+		uint64_t white;
+	} pixel;
+};
+
+enum app_err_code {
+	APP_ERR_OK = 0,
+	APP_ERR_FAILED_OPEN_DISPLAY
+};
+
+struct app_err {
+	enum app_err_code code;
+	const char *name;
+};
+
+struct app app_init(uint32_t width, uint32_t height, struct app_err *err);
+void app_close(struct app app);
+
+void _app_err_set(struct app_err *err, enum app_err_code code);
+
+int
+main(int argc, char *argv[])
+{
+	struct app_err aerr = {0};
+	struct app app = {0};
+
+	app = app_init(800, 600, &aerr);
+	if ( aerr.code != APP_ERR_OK ) {
+		fprintf(stderr, "Failed to init app: `%s`\n", aerr.name);
+		exit(EXIT_FAILURE);
+	}
+
+	app_close(app);
+	printf("Hello World!\n");
+	(void) argc; (void) argv;
+	return 0;
+}
+
+struct app
+app_init(uint32_t width, uint32_t height, struct app_err *err)
+{
+	struct app empty_app = {0};
+	struct app app = {0};
+
+	app.win.size.w = width;
+	app.win.size.h = height;
+
+	app.dis = XOpenDisplay(NULL);
+	if ( app.dis == NULL ) {
+		_app_err_set(err, APP_ERR_FAILED_OPEN_DISPLAY);
+		return empty_app;
+	}
+	app.screen = XDefaultScreen(app.dis);
+
+	app.root_win = XDefaultRootWindow(app.dis);
+
+	app.pixel.black = XBlackPixel(app.dis, app.screen);
+	app.pixel.white = XWhitePixel(app.dis, app.screen);
+
+	app.win.it = XCreateSimpleWindow(app.dis, app.root_win,
+					app.win.pos.x, app.win.pos.y,
+					app.win.size.w, app.win.size.h,
+					5, app.pixel.black, app.pixel.white);
+
+	app.gc = XDefaultGC(app.dis, app.screen);
+
+
+	return app;
+}
+
+void 
+app_close(struct app app)
+{
+	XCloseDisplay(app.dis);
+}
+
+void 
+_app_err_set(struct app_err *err, enum app_err_code code)
+{
+	if ( err == NULL ) {
+		return ;
+	}
+
+	err->code = code;
+	switch ( code ) {
+#define _APP_ERR_SET_CASE(code) case code: err->name = #code; break
+
+	_APP_ERR_SET_CASE(APP_ERR_OK);
+	_APP_ERR_SET_CASE(APP_ERR_FAILED_OPEN_DISPLAY);
+
+#undef _APP_ERR_SET_CASE
+	}
+}