From 87371ce93411ba900c83cd8230a5814b59092c4b Mon Sep 17 00:00:00 2001
From: shan <shankern@protonmail.com>
Date: Fri, 7 Oct 2022 13:06:06 -0700
Subject: Fixed an edge case where when gradient start/end are identical the GL
fragment shader was not choosing the appropriate color.
---
glow/src/shader/common/gradient.frag | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)
(limited to 'glow/src/shader')
diff --git a/glow/src/shader/common/gradient.frag b/glow/src/shader/common/gradient.frag
index 3c701af7..82c7e251 100644
--- a/glow/src/shader/common/gradient.frag
+++ b/glow/src/shader/common/gradient.frag
@@ -27,27 +27,33 @@ void main() {
vec2 current_vec = vec2(raw_position.xy - start);
vec2 unit = normalize(gradient_vec);
float coord_offset = dot(unit, current_vec) / length(gradient_vec);
+ //if a gradient has a start/end stop that is identical, the mesh will have a transparent fill
+ fragColor = vec4(0.0, 0.0, 0.0, 0.0);
- for (uint i = 0; i < color_stops_size - 2; i += 2) {
- vec4 color = color_stops[i];
- float offset = color_stops[i+1].x;
+ float min_offset = color_stops[1].x;
+ float max_offset = color_stops[color_stops_size - 1].x;
- vec4 next_color = color_stops[i+2];
+ for (uint i = 0; i < color_stops_size - 2; i += 2) {
+ float curr_offset = color_stops[i+1].x;
float next_offset = color_stops[i+3].x;
- if (offset <= coord_offset && coord_offset <= next_offset) {
- fragColor = mix(color, next_color, smoothstep(
- offset,
+ if (coord_offset <= min_offset) {
+ //current coordinate is before the first defined offset, set it to the start color
+ fragColor = color_stops[0];
+ }
+
+ if (curr_offset <= coord_offset && coord_offset <= next_offset) {
+ //current fragment is between the current offset processing & the next one, interpolate colors
+ fragColor = mix(color_stops[i], color_stops[i+2], smoothstep(
+ curr_offset,
next_offset,
coord_offset
));
- } else if (coord_offset < color_stops[1].x) {
- fragColor = color_stops[0];
- } else if (coord_offset > color_stops[color_stops_size - 1].x) {
+ }
+
+ if (coord_offset >= max_offset) {
+ //current coordinate is before the last defined offset, set it to the last color
fragColor = color_stops[color_stops_size - 2];
- } else {
- //This use case can happen if a gradient's start & end position are the same
- fragColor = vec4(0.0, 0.0, 0.0, 0.0);
}
}
}
--
cgit