fix line-trim-offset shader (#12017) (#12018)

* fix line-trim-offset shader * fix line-trim-offset check Co-authored-by: Stepan Kuzmin <[email protected]>
mapbox · Jun 20, 2022 · e46f4a2 · e46f4a2
1 parent 9fc5327
commit e46f4a2
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/src/render/program/line_program.js b/src/render/program/line_program.js
@@ -157,7 +157,11 @@ const lineDefinesValues = (layer: LineStyleLayer): LineDefinesType[] => {
     const values = [];
     if (hasDash(layer)) values.push('RENDER_LINE_DASH');
     if (layer.paint.get('line-gradient')) values.push('RENDER_LINE_GRADIENT');
-    if (layer.paint.get('line-trim-offset')) values.push('RENDER_LINE_TRIM_OFFSET');
+
+    const trimOffset = layer.paint.get('line-trim-offset');
+    if (trimOffset[0] !== 0 || trimOffset[1] !== 0) {
+        values.push('RENDER_LINE_TRIM_OFFSET');
+    }
 
     const hasPattern = layer.paint.get('line-pattern').constantOr((1: any));
     const hasOpacity = layer.paint.get('line-opacity').constantOr(1.0) !== 1.0;

diff --git a/src/shaders/line.fragment.glsl b/src/shaders/line.fragment.glsl
@@ -71,8 +71,13 @@ void main() {
     // Mark the pixel to be transparent when:
     // 1. trim_offset range is valid
     // 2. line_progress is within trim_offset range
-    if (trim_end > trim_start && (line_progress <= trim_end && line_progress >= trim_start)) {
-        out_color = vec4(0, 0, 0, 0);
+
+    // Nested conditionals fixes the issue
+    // https://github.com/mapbox/mapbox-gl-js/issues/12013
+    if (trim_end > trim_start) {
+        if (line_progress <= trim_end && line_progress >= trim_start) {
+            out_color = vec4(0, 0, 0, 0);
+        }
     }
 #endif