diff options
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/drm_rect.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c index 22091ecdbff4..dc11a2867f20 100644 --- a/drivers/gpu/drm/drm_rect.c +++ b/drivers/gpu/drm/drm_rect.c @@ -94,3 +94,180 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst, return drm_rect_intersect(dst, clip); } EXPORT_SYMBOL(drm_rect_clip_scaled); + +static int drm_calc_scale(int src, int dst) +{ + int scale = 0; + + if (src < 0 || dst < 0) + return -EINVAL; + + if (dst == 0) + return 0; + + scale = src / dst; + + return scale; +} + +/** + * drm_rect_calc_hscale - calculate the horizontal scaling factor + * @src: source window rectangle + * @dst: destination window rectangle + * @min_hscale: minimum allowed horizontal scaling factor + * @max_hscale: maximum allowed horizontal scaling factor + * + * Calculate the horizontal scaling factor as + * (@src width) / (@dst width). + * + * RETURNS: + * The horizontal scaling factor, or errno of out of limits. + */ +int drm_rect_calc_hscale(const struct drm_rect *src, + const struct drm_rect *dst, + int min_hscale, int max_hscale) +{ + int src_w = drm_rect_width(src); + int dst_w = drm_rect_width(dst); + int hscale = drm_calc_scale(src_w, dst_w); + + if (hscale < 0 || dst_w == 0) + return hscale; + + if (hscale < min_hscale || hscale > max_hscale) + return -ERANGE; + + return hscale; +} +EXPORT_SYMBOL(drm_rect_calc_hscale); + +/** + * drm_rect_calc_vscale - calculate the vertical scaling factor + * @src: source window rectangle + * @dst: destination window rectangle + * @min_vscale: minimum allowed vertical scaling factor + * @max_vscale: maximum allowed vertical scaling factor + * + * Calculate the vertical scaling factor as + * (@src height) / (@dst height). + * + * RETURNS: + * The vertical scaling factor, or errno of out of limits. + */ +int drm_rect_calc_vscale(const struct drm_rect *src, + const struct drm_rect *dst, + int min_vscale, int max_vscale) +{ + int src_h = drm_rect_height(src); + int dst_h = drm_rect_height(dst); + int vscale = drm_calc_scale(src_h, dst_h); + + if (vscale < 0 || dst_h == 0) + return vscale; + + if (vscale < min_vscale || vscale > max_vscale) + return -ERANGE; + + return vscale; +} +EXPORT_SYMBOL(drm_rect_calc_vscale); + +/** + * drm_calc_hscale_relaxed - calculate the horizontal scaling factor + * @src: source window rectangle + * @dst: destination window rectangle + * @min_hscale: minimum allowed horizontal scaling factor + * @max_hscale: maximum allowed horizontal scaling factor + * + * Calculate the horizontal scaling factor as + * (@src width) / (@dst width). + * + * If the calculated scaling factor is below @min_vscale, + * decrease the height of rectangle @dst to compensate. + * + * If the calculated scaling factor is above @max_vscale, + * decrease the height of rectangle @src to compensate. + * + * RETURNS: + * The horizontal scaling factor. + */ +int drm_rect_calc_hscale_relaxed(struct drm_rect *src, + struct drm_rect *dst, + int min_hscale, int max_hscale) +{ + int src_w = drm_rect_width(src); + int dst_w = drm_rect_width(dst); + int hscale = drm_calc_scale(src_w, dst_w); + + if (hscale < 0 || dst_w == 0) + return hscale; + + if (hscale < min_hscale) { + int max_dst_w = src_w / min_hscale; + + drm_rect_adjust_size(dst, max_dst_w - dst_w, 0); + + return min_hscale; + } + + if (hscale > max_hscale) { + int max_src_w = dst_w * max_hscale; + + drm_rect_adjust_size(src, max_src_w - src_w, 0); + + return max_hscale; + } + + return hscale; +} +EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed); + +/** + * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor + * @src: source window rectangle + * @dst: destination window rectangle + * @min_vscale: minimum allowed vertical scaling factor + * @max_vscale: maximum allowed vertical scaling factor + * + * Calculate the vertical scaling factor as + * (@src height) / (@dst height). + * + * If the calculated scaling factor is below @min_vscale, + * decrease the height of rectangle @dst to compensate. + * + * If the calculated scaling factor is above @max_vscale, + * decrease the height of rectangle @src to compensate. + * + * RETURNS: + * The vertical scaling factor. + */ +int drm_rect_calc_vscale_relaxed(struct drm_rect *src, + struct drm_rect *dst, + int min_vscale, int max_vscale) +{ + int src_h = drm_rect_height(src); + int dst_h = drm_rect_height(dst); + int vscale = drm_calc_scale(src_h, dst_h); + + if (vscale < 0 || dst_h == 0) + return vscale; + + if (vscale < min_vscale) { + int max_dst_h = src_h / min_vscale; + + drm_rect_adjust_size(dst, 0, max_dst_h - dst_h); + + return min_vscale; + } + + if (vscale > max_vscale) { + int max_src_h = dst_h * max_vscale; + + drm_rect_adjust_size(src, 0, max_src_h - src_h); + + return max_vscale; + } + + return vscale; +} +EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed); |