diff options
| author | Jeff Smith <whydoubt@gmail.com> | 2018-01-26 06:25:19 -0600 |
|---|---|---|
| committer | Adam Jackson <ajax@redhat.com> | 2018-02-12 14:52:09 -0500 |
| commit | 38e6fb757386e2cb2c51a27e52346473d4ffb9a1 (patch) | |
| tree | 440c48e31086fa294974c481ddce65c3297bd8f1 /glamor | |
| parent | f6cd99ed79c17e3aa04b8821d10ca95939bd8675 (diff) | |
glamor: fix repeat-reflect case in linear gradient shader
If _pt_distance is negative, it causes the final distance to be negative
in the repeat-reflect case. Moving the scaling by _pt_distance earlier
avoids this problem, and simplifies some equations as a bonus.
Bugzilla: https://bugs.freedesktop.org/98508
Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
(cherry picked from commit 3e377e238f7257fd01e56a4a25dfd77e033673e4)
Diffstat (limited to 'glamor')
| -rw-r--r-- | glamor/glamor_gradient.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/glamor/glamor_gradient.c b/glamor/glamor_gradient.c index 0c97ce7cb..14ff9173f 100644 --- a/glamor/glamor_gradient.c +++ b/glamor/glamor_gradient.c @@ -458,7 +458,6 @@ _glamor_create_linear_gradient_program(ScreenPtr screen, int stops_count, "float get_stop_len()\n"\ "{\n"\ " vec3 tmp = vec3(source_texture.x, source_texture.y, 1.0);\n"\ - " float len_percentage;\n"\ " float distance;\n"\ " float _p1_distance;\n"\ " float _pt_distance;\n"\ @@ -484,19 +483,17 @@ _glamor_create_linear_gradient_program(ScreenPtr screen, int stops_count, " _pt_distance = pt_distance * source_texture_trans.z;\n"\ " } \n"\ " \n"\ - " distance = distance - _p1_distance; \n"\ + " distance = (distance - _p1_distance) / _pt_distance;\n"\ " \n"\ " if(repeat_type == %d){\n" /* repeat normal*/\ - " distance = mod(distance, _pt_distance);\n"\ + " distance = fract(distance);\n"\ " }\n"\ " \n"\ " if(repeat_type == %d) {\n" /* repeat reflect*/\ - " distance = abs(mod(distance + _pt_distance, 2.0 * _pt_distance) - _pt_distance);\n"\ + " distance = abs(fract(distance * 0.5 + 0.5) * 2.0 - 1.0);\n"\ " }\n"\ " \n"\ - " len_percentage = distance/(_pt_distance);\n"\ - " \n"\ - " return len_percentage;\n"\ + " return distance;\n"\ "}\n"\ "\n"\ "void main()\n"\ |