add snow (graphics demo)

apps/snow.c

@@ -0,0 +1,182 @@
+/* vim: tabstop=4 shiftwidth=4 noexpandtab
+ * This file is part of ToaruOS and is released under the terms
+ * of the NCSA / University of Illinois License - see LICENSE.md
+ * Copyright (C) 2018 K. Lange
+ */
+#include <stdlib.h>
+#include <assert.h>
+#include <unistd.h>
+#include <time.h>
+#include <sched.h>
+#include <math.h>
+
+#include <sys/fswait.h>
+#include <sys/time.h>
+
+#include <toaru/yutani.h>
+#include <toaru/graphics.h>
+
+static yutani_t * yctx;
+static yutani_window_t * wina;
+static gfx_context_t * ctx;
+static int should_exit = 0;
+static sprite_t snowflake;
+
+#define FLAKES 40
+#define FALL_SPEED 3
+
+struct {
+	int16_t x;
+	int16_t y;
+	uint8_t rotation;
+	uint8_t alpha;
+	int8_t wind;
+	uint8_t exists;
+} flakes[FLAKES];
+
+int flakes_made = 0;
+
+static void add_flake() {
+	for (int i = 0; i < FLAKES; ++i) {
+		if (!flakes[i].exists) {
+			flakes[i].exists = 1;
+			flakes[i].y = -snowflake.height / 2;
+			flakes[i].x = rand() % (ctx->width);
+			flakes[i].alpha = rand() % 50 + 50;
+			flakes[i].rotation = rand() % 255;
+			flakes[i].wind = (rand() % 6) - 3;
+			return;
+		}
+	}
+}
+
+static void draw(void) {
+	draw_fill(ctx, 0);
+	for (int i = 0; i < FLAKES; ++i) {
+		if (flakes[i].exists) {
+			draw_sprite_rotate(ctx, &snowflake,
+					flakes[i].x, flakes[i].y,
+					(float)(flakes[i].rotation)  / 100.0,
+					(float)(flakes[i].alpha) / 100.0);
+			flakes[i].y += FALL_SPEED;
+			flakes[i].x += flakes[i].wind;
+			if (flakes[i].y >= ctx->height + snowflake.height / 2 ||
+				flakes[i].x <= -snowflake.width / 2 ||
+				flakes[i].x >= ctx->width + snowflake.width / 2) {
+				flakes[i].exists = 0;
+				add_flake();
+			}
+		}
+	}
+	flip(ctx);
+	yutani_flip(yctx, wina);
+}
+
+void resize_finish(int w, int h) {
+	yutani_window_resize_accept(yctx, wina, w, h);
+	reinit_graphics_yutani(ctx, wina);
+	draw();
+	yutani_window_resize_done(yctx, wina);
+}
+
+uint64_t last_flake = 0;
+
+static uint64_t precise_current_time(void) {
+	struct timeval t;
+	gettimeofday(&t, NULL);
+
+	time_t sec_diff = t.tv_sec;
+	suseconds_t usec_diff = t.tv_usec;
+
+	return (uint64_t)(sec_diff * 1000 + usec_diff / 1000);
+}
+
+static uint64_t precise_time_since(uint64_t start_time) {
+
+	uint32_t now = precise_current_time();
+	uint32_t diff = now - start_time; /* Milliseconds */
+
+	return diff;
+}
+
+int main (int argc, char ** argv) {
+	srand(time(NULL));
+	memset(&flakes, 0, sizeof(flakes));
+
+	yctx = yutani_init();
+	if (!yctx) {
+		fprintf(stderr, "%s: failed to connect to compositor\n", argv[0]);
+		return 1;
+	}
+
+	load_sprite(&snowflake, "/usr/share/snowflake.bmp");
+	snowflake.alpha = ALPHA_EMBEDDED;
+	snowflake.masks = NULL;
+	snowflake.blank = 0;
+
+	wina = yutani_window_create(yctx, 100, 100);
+	if (argc < 2 || strcmp(argv[1],"--no-ad")) {
+		yutani_window_advertise(yctx, wina, "snow");
+	}
+	yutani_special_request(yctx, wina, YUTANI_SPECIAL_REQUEST_MAXIMIZE);
+	yutani_window_update_shape(yctx, wina, 256);
+
+	ctx = init_graphics_yutani_double_buffer(wina);
+	draw_fill(ctx, rgba(0,0,0,0));
+	flip(ctx);
+
+	while (!should_exit) {
+		int fds[1] = {fileno(yctx->sock)};
+		int index = fswait2(1,fds,10);
+		if (index == 0) {
+			yutani_msg_t * m = yutani_poll(yctx);
+			while (m) {
+				switch (m->type) {
+					case YUTANI_MSG_KEY_EVENT:
+						{
+							struct yutani_msg_key_event * ke = (void*)m->data;
+							if (ke->event.action == KEY_ACTION_DOWN && ke->event.keycode == 'q') {
+								should_exit = 1;
+								sched_yield();
+							}
+						}
+						break;
+					case YUTANI_MSG_WINDOW_MOUSE_EVENT:
+						{
+							struct yutani_msg_window_mouse_event * me = (void*)m->data;
+							if (me->command == YUTANI_MOUSE_EVENT_DOWN && me->buttons & YUTANI_MOUSE_BUTTON_LEFT) {
+								yutani_window_drag_start(yctx, wina);
+							}
+						}
+						break;
+					case YUTANI_MSG_RESIZE_OFFER:
+						{
+							struct yutani_msg_window_resize * wr = (void*)m->data;
+							resize_finish(wr->width, wr->height);
+						}
+						break;
+					case YUTANI_MSG_WINDOW_CLOSE:
+					case YUTANI_MSG_SESSION_END:
+						should_exit = 1;
+						break;
+					default:
+						break;
+				}
+				free(m);
+				m = yutani_poll_async(yctx);
+			}
+		} else {
+			if (flakes_made < 20 && precise_time_since(last_flake) > 1000) {
+				add_flake();
+				flakes_made += 1;
+				last_flake = precise_current_time();
+			}
+		}
+		draw();
+	}
+
+	yutani_close(yctx, wina);
+
+	return 0;
+}
+