#include #include 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; }