user/dvd: dumb animation demo

1 files changed, 75 insertions, 0 deletions

diff --git a/src/user/app/dvd/dvd.c b/src/user/app/dvd/dvd.c
new file mode 100644
index 0000000..73ac2c9
--- /dev/null
+++ b/src/user/app/dvd/dvd.c
@@ -0,0 +1,75 @@
+#include <camellia/syscalls.h>
+#include <stdlib.h>
+
+struct framebuf {
+	size_t len, width, height, pitch;
+	char *b;
+};
+struct framebuf fb;
+handle_t fb_fd;
+
+struct rect {
+	uint32_t x1, y1, x2, y2;
+};
+struct rect dirty;
+
+void dirty_mark(uint32_t x, uint32_t y) {
+	if (dirty.x1 > x) dirty.x1 = x;
+	if (dirty.x2 < x) dirty.x2 = x;
+	if (dirty.y1 > y) dirty.y1 = y;
+	if (dirty.y2 < y) dirty.y2 = y;
+}
+
+void flush(void) {
+	size_t low, high;
+	if (~dirty.x1 == 0) return;
+
+	// not optimal, on larger display widths it'd be more efficient to split this up into multiple writes
+	low  = fb.pitch * (dirty.y1  ) + 4 * (dirty.x1  );
+	high = fb.pitch * (dirty.y2+1) + 4 * (dirty.x2+1) + 3;
+
+	if (~dirty.y2 == 0) high = fb.len;
+	if (high > fb.len)  high = fb.len;
+
+	_syscall_write(fb_fd, fb.b + low, high - low, low, 0);
+
+	dirty.x1 = ~0; dirty.y1 = ~0;
+	dirty.x2 =  0; dirty.y2 =  0;
+}
+
+void draw_rect(uint32_t x, uint32_t y, uint32_t w, uint32_t h, uint32_t col) {
+	for (uint32_t i = 0; i < w; i++) {
+		for (uint32_t j = 0; j < h; j++) {
+			*((uint32_t*)(fb.b + fb.pitch * (y+j) + 4 * (x+i))) = col;
+		}
+	}
+	if (dirty.x1 > x) dirty.x1 = x;
+	if (dirty.y1 > y) dirty.y1 = y;
+	if (dirty.x2 < x + w) dirty.x2 = x + w;
+	if (dirty.y2 < y + h) dirty.y2 = y + h;
+}
+
+int main(void) {
+	fb_fd = _syscall_open("/kdev/video/b", 13, 0);
+	// TODO don't hardcode framebuffer size
+	fb.len = 640 * 480 * 4;
+	fb.width = 640;
+	fb.height = 480;
+	fb.pitch = 640 * 4;
+	fb.b = malloc(fb.len);
+
+	int dx = 2, dy = 2, x = 100, y = 100, w = 150, h = 70;
+	uint32_t col = 0x800000;
+
+	for (;;) {
+		if (x + dx < 0 || x + dx + w >= fb.width ) dx *= -1;
+		if (y + dy < 0 || y + dy + h >= fb.height) dy *= -1;
+		x += dx;
+		y += dy;
+		draw_rect(x, y, w, h, col++);
+		flush();
+		_syscall_sleep(1000 / 60);
+	}
+
+	return 1;
+}