xlib_playground

commit 062ae436f429e77fe0b1a45b043e27f072399f6c
parent b531b9293c5396d1220e52c084455f53aacfc405
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Fri, 23 Dec 2022 09:25:10 +0900

copy ex2

Diffstat:
A
ex3/Makefile
 | 
14
++++++++++++++
A
ex3/ex2.c
 | 
215
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 229 insertions(+), 0 deletions(-)
diff --git a/ex3/Makefile b/ex3/Makefile
@@ -0,0 +1,14 @@
+INCS=-I/usr/X11R6/include
+CFLAGS=-Wall -Wextra -std=c11
+LIBS=-L/usr/X11R6/lib -lX11 -lXext -lm
+IN=*.c
+OUT=ex2
+
+all: $(IN)
+	$(CC) $(INCS) $(CFLAGS) -o $(OUT) $(IN) $(LIBS)
+
+run: all
+	./$(OUT)
+
+clean:
+	rm -f $(OUT)
diff --git a/ex3/ex2.c b/ex3/ex2.c
@@ -0,0 +1,215 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <math.h>
+
+#include <X11/Xlib.h>
+
+/* macros */
+#define INIT_WIDTH 800
+#define INIT_HEIGHT 600
+#define FPS 60
+
+/*
+#define COUNT_FPS
+*/
+
+
+enum Keys {
+	Key_D,
+    Key_S,
+    Key_A,
+    Key_W,
+    Key_Space,
+    Num_Key, //number of keys in this enum
+};
+enum Key_State {
+    Key_Up,
+    Key_Down,
+};
+
+/* variables */
+Display     *display;
+Window       window;
+unsigned int win_width = INIT_WIDTH, win_height = INIT_HEIGHT;
+GC           gc;
+Atom         wm_delete_window;
+int          key_state[Num_Key];
+int          quit;
+float        px = 200, py = 200;
+float        vx = 0, vy = 0;
+int          width = 40, height = 40;
+
+
+/* function prototypes */
+void setup(void);
+void cleanup(void);
+void handle_inputs(void);
+
+
+void
+setup(void)
+{
+	if ((display = XOpenDisplay(NULL)) == NULL){
+	    fprintf(stderr, "ERROR: could not open display\n");
+	    exit(1);
+	}
+	window = XCreateSimpleWindow(
+	                    display,
+	                    XDefaultRootWindow(display),
+	                    0, 0,
+	                    win_width, win_height,
+	                    0, 0,
+						0);
+	XStoreName(display, window, "UNKO");
+	gc = XCreateGC(display, window, 0, NULL);
+
+	wm_delete_window = XInternAtom(display, 
+	                               "WM_DELETE_WINDOW", False);
+	XSetWMProtocols(display, window, &wm_delete_window, 1);
+
+	XSelectInput(display, window,
+	             ExposureMask|KeyPressMask|KeyReleaseMask);
+	
+	XSetForeground(display, gc, 0x00FFFF);
+	XMapWindow(display, window);
+}
+
+void
+handle_inputs(void)
+{
+	XEvent event;
+	while (XPending(display) > 0) {
+		XNextEvent(display, &event);
+		switch (event.type) {
+		case KeyPress: {
+			switch (XLookupKeysym(&event.xkey, 0)) {
+			case 'q':
+				quit = 1;
+				break;
+			case 'd':
+				key_state[Key_D] = Key_Down;
+				break;
+			case 'a':
+				key_state[Key_A] = Key_Down;
+				break;
+			case 'w':
+				key_state[Key_W] = Key_Down;
+				break;
+			case 's':
+				key_state[Key_S] = Key_Down;
+				break;
+			default:
+				break;
+			}
+		} break;
+		case KeyRelease: {
+			switch (XLookupKeysym(&event.xkey, 0)) {
+			case 'd':
+				key_state[Key_D] = Key_Up;
+				break;
+			case 'a':
+				key_state[Key_A] = Key_Up;
+				break;
+			case 'w':
+				key_state[Key_W] = Key_Up;
+				break;
+			case 's':
+				key_state[Key_S] = Key_Up;
+				break;
+			default:
+				break;
+			}
+		} break;
+		case ClientMessage: {
+			if ((Atom) event.xclient.data.l[0] == wm_delete_window) {
+				quit = 1;
+			}
+		} break;
+		default:
+			break;
+		}
+	}
+
+
+	vx = vy = 0;
+	if (key_state[Key_D] == Key_Down)
+		vx += 300;
+	if (key_state[Key_A] == Key_Down)
+		vx += -300;
+	if (key_state[Key_S] == Key_Down)
+		vy += 300;
+	if (key_state[Key_W] == Key_Down)
+		vy += -300;
+
+}
+
+void
+cleanup(void)
+{
+	XCloseDisplay(display);
+}
+
+int
+main(void)
+{
+	long t0, t1, dt;
+#ifdef COUNT_FPS
+	int fps_count = 0;
+#endif
+	struct timespec ts;
+
+	setup();
+	quit = 0;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	t0 = ts.tv_nsec;
+
+	while (!quit){
+		handle_inputs();
+
+		// fix fps
+		dt = 0;
+		while (dt < 1.0 * 1000 * 1000 * 1000 / FPS){
+			clock_gettime(CLOCK_MONOTONIC, &ts);
+			t1 = ts.tv_nsec;
+			dt = t1 > t0 ? t1 - t0 : t1 - t0 + 1000 * 1000 * 1000;
+		}
+#ifdef COUNT_FPS
+		// count fps.
+		// simple but not precise.
+		fps_count++;
+		if (t1 < t0){
+			printf("fps: %u\n", fps_count);
+			fps_count = 0;
+		}
+#endif
+
+		clock_gettime(CLOCK_MONOTONIC, &ts);
+		t0 = ts.tv_nsec;
+
+		px = px + vx * dt / 1000 / 1000 / 1000;
+		py = py + vy * dt / 1000 / 1000 / 1000; 
+		// bind within the window
+		if (px < 0)
+			px = 0;
+		if (win_width < px + width)
+			px = win_width - width;
+		if (py < 0)
+			py = 0;
+		if (win_height < py + height)
+			py = win_height - height;
+
+		XClearArea(display, window,
+				   0, 0,                  // position
+				   win_width, win_height, // width and height
+				   False);
+		XFillRectangle(display, window, gc,
+					   px, py,    // position
+					   width, height);   // width and height
+
+	}
+
+	cleanup();
+	return 0;
+}