static void src_dst_split_scaling(int src_size, int dst_size,
int scaled_src_size, bool unscaled,
float zoom, float align, float pan,
int *src_start, int *src_end,
int *dst_start, int *dst_end,
int *osd_margin_a, int *osd_margin_b)
{
if (unscaled) {
scaled_src_size = src_size;
zoom = 0.0;
}
scaled_src_size *= powf(2, zoom);
align = (align + 1) / 2;
*src_start = 0;
*src_end = src_size;
*dst_start = (dst_size - scaled_src_size) * align + pan * scaled_src_size;
*dst_end = *dst_start + scaled_src_size;
// Distance of screen frame to video
*osd_margin_a = *dst_start;
*osd_margin_b = dst_size - *dst_end;
// Clip to screen
int s_src = *src_end - *src_start;
int s_dst = *dst_end - *dst_start;
if (*dst_start < 0) {
int border = -(*dst_start) * s_src / s_dst;
*src_start += border;
*dst_start = 0;
}
if (*dst_end > dst_size) {
int border = (*dst_end - dst_size) * s_src / s_dst;
*src_end -= border;
*dst_end = dst_size;
}
if (unscaled) {
// Force unscaled by reducing the range for src or dst
int src_s = *src_end - *src_start;
int dst_s = *dst_end - *dst_start;
if (src_s > dst_s) {
*src_end = *src_start + dst_s;
} else if (src_s < dst_s) {
*dst_end = *dst_start + src_s;
}
}
// For sanity: avoid bothering VOs with corner cases
clamp_size(src_size, src_start, src_end);
clamp_size(dst_size, dst_start, dst_end);
}
size_t File::read(uint8_t *buf, size_t n) {
size_t acquired;
osalDbgAssert(NULL != this->mtd, "File not opened");
osalDbgCheck(NULL != buf);
n = clamp_size(n);
if (0 == n)
return 0;
acquired = mtd->read(buf, n, tip + start);
tip += acquired;
return acquired;
}
size_t File::write(const uint8_t *buf, size_t n) {
size_t written;
osalDbgAssert(NULL != this->mtd, "File not opened");
osalDbgCheck(NULL != buf);
n = clamp_size(n);
if (0 == n)
return 0;
written = mtd->write(buf, n, tip + start);
tip += written;
return written;
}