From 7df7db97fdda2ea6f8617882cd5202575f44bfc5 Mon Sep 17 00:00:00 2001 From: Grigori Goronzy Date: Wed, 6 Jan 2010 23:51:01 +0100 Subject: Improve rotation cache accuracy In some cases 16.16 precision is not good enough. Instead use 10.22 and use modulo 360.0 on the angles to make overflows impossible and improve cache hit ratio sometimes. --- libass/ass_render.c | 6 +++--- libass/ass_utils.h | 15 +++++++++++++++ 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/libass/ass_render.c b/libass/ass_render.c index 1dc347f..22edce8 100644 --- a/libass/ass_render.c +++ b/libass/ass_render.c @@ -1915,11 +1915,11 @@ ass_render_event(ASS_Renderer *render_priv, ASS_Event *event, text_info->glyphs[text_info->length].hash_key.scale_y = render_priv->state.scale_y * 0xFFFF; text_info->glyphs[text_info->length].hash_key.frx = - render_priv->state.frx * 0xFFFF; + rot_key(render_priv->state.frx); text_info->glyphs[text_info->length].hash_key.fry = - render_priv->state.fry * 0xFFFF; + rot_key(render_priv->state.fry); text_info->glyphs[text_info->length].hash_key.frz = - render_priv->state.frz * 0xFFFF; + rot_key(render_priv->state.frz); text_info->glyphs[text_info->length].hash_key.fax = render_priv->state.fax * 0xFFFF; text_info->glyphs[text_info->length].hash_key.fay = diff --git a/libass/ass_utils.h b/libass/ass_utils.h index f5c68e9..ad8574c 100644 --- a/libass/ass_utils.h +++ b/libass/ass_utils.h @@ -102,6 +102,21 @@ static inline int double_to_d16(double x) { return (int) (x * 0x10000); } +static inline double d22_to_double(int x) +{ + return ((double) x) / 0x400000; +} +static inline int double_to_d22(double x) +{ + return (int) (x * 0x400000); +} + +// Calculate cache key for a rotational angle in degrees +static inline int rot_key(double a) +{ + const int m = double_to_d22(360.0); + return double_to_d22(a) % m; +} #define FNV1_32A_INIT (unsigned)0x811c9dc5 -- cgit v1.2.3