Fixed asymmetrical range with scanline mode, version 1.4

Chlumsky · Chlumsky · commit 2ede254314a2 · 2026-03-05T15:06:50.000+01:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,4 +1,15 @@
 
+## Version 1.4 (2026-03-05)
+
+- Updated to MSDFgen 1.13
+    - Improved BMP file output - support for BGRA (`mtsdf` mode), optimized size of grayscale files
+    - Fixed incorrect output with asymmetrical distance range when inversion occurs due to scanline pass (`-scanline`)
+    - Improved precision of cubic curve distance computation
+    - Fixed a bug incorrectly adjusting convergent edge segments in shape normalization
+    - The library now operates on bitmap section references (instead of contiguous bitmap references), which makes it possible to generate a distance field directly into a subsection of a larger bitmap or a bitmap with the opposite row ordering
+- Updated Shadron preview output
+- Fixed a bug in `FontGeometry` constructor
+
 ## Version 1.3 (2024-06-01)
 
 - Updated to MSDFgen 1.12
diff --git a/LICENSE.txt b/LICENSE.txt
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2020 - 2025 Viktor Chlumsky
+Copyright (c) 2020 - 2026 Viktor Chlumsky
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/msdf-atlas-gen/Workload.cpp b/msdf-atlas-gen/Workload.cpp
@@ -20,10 +20,10 @@ bool Workload::finishSequential() {
 }
 
 bool Workload::finishParallel(int threadCount) {
-    bool result = true;
+    std::atomic<bool> result(true);
     std::atomic<int> next(0);
     std::function<void(int)> threadWorker = [this, &result, &next](int threadNo) {
-        for (int i = next++; result && i < chunks; i = next++) {
+        for (int i = next++; i < chunks && result; i = next++) {
             if (!workerFunction(i, threadNo))
                 result = false;
         }
diff --git a/msdf-atlas-gen/glyph-generators.cpp b/msdf-atlas-gen/glyph-generators.cpp
@@ -3,20 +3,25 @@
 
 namespace msdf_atlas {
 
+static float sdfZeroValue(const GlyphGeometry &glyph) {
+    msdfgen::Range range = glyph.getBoxRange();
+    return range.lower != range.upper ? float(range.lower/(range.lower-range.upper)) : .5f;
+}
+
 void scanlineGenerator(const msdfgen::BitmapSection<float, 1> &output, const GlyphGeometry &glyph, const GeneratorAttributes &attribs) {
     msdfgen::rasterize(output, glyph.getShape(), glyph.getBoxScale(), glyph.getBoxTranslate(), MSDF_ATLAS_GLYPH_FILL_RULE);
 }
 
 void sdfGenerator(const msdfgen::BitmapSection<float, 1> &output, const GlyphGeometry &glyph, const GeneratorAttributes &attribs) {
     msdfgen::generateSDF(output, glyph.getShape(), glyph.getBoxProjection(), glyph.getBoxRange(), attribs.config);
     if (attribs.scanlinePass)
-        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), MSDF_ATLAS_GLYPH_FILL_RULE);
+        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), sdfZeroValue(glyph), MSDF_ATLAS_GLYPH_FILL_RULE);
 }
 
 void psdfGenerator(const msdfgen::BitmapSection<float, 1> &output, const GlyphGeometry &glyph, const GeneratorAttributes &attribs) {
     msdfgen::generatePSDF(output, glyph.getShape(), glyph.getBoxProjection(), glyph.getBoxRange(), attribs.config);
     if (attribs.scanlinePass)
-        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), MSDF_ATLAS_GLYPH_FILL_RULE);
+        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), sdfZeroValue(glyph), MSDF_ATLAS_GLYPH_FILL_RULE);
 }
 
 void msdfGenerator(const msdfgen::BitmapSection<float, 3> &output, const GlyphGeometry &glyph, const GeneratorAttributes &attribs) {
@@ -25,7 +30,7 @@ void msdfGenerator(const msdfgen::BitmapSection<float, 3> &output, const GlyphGe
         config.errorCorrection.mode = msdfgen::ErrorCorrectionConfig::DISABLED;
     msdfgen::generateMSDF(output, glyph.getShape(), glyph.getBoxProjection(), glyph.getBoxRange(), config);
     if (attribs.scanlinePass) {
-        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), MSDF_ATLAS_GLYPH_FILL_RULE);
+        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), sdfZeroValue(glyph), MSDF_ATLAS_GLYPH_FILL_RULE);
         if (attribs.config.errorCorrection.mode != msdfgen::ErrorCorrectionConfig::DISABLED) {
             config.errorCorrection.mode = attribs.config.errorCorrection.mode;
             config.errorCorrection.distanceCheckMode = msdfgen::ErrorCorrectionConfig::DO_NOT_CHECK_DISTANCE;
@@ -40,7 +45,7 @@ void mtsdfGenerator(const msdfgen::BitmapSection<float, 4> &output, const GlyphG
         config.errorCorrection.mode = msdfgen::ErrorCorrectionConfig::DISABLED;
     msdfgen::generateMTSDF(output, glyph.getShape(), glyph.getBoxProjection(), glyph.getBoxRange(), config);
     if (attribs.scanlinePass) {
-        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), MSDF_ATLAS_GLYPH_FILL_RULE);
+        msdfgen::distanceSignCorrection(output, glyph.getShape(), glyph.getBoxProjection(), sdfZeroValue(glyph), MSDF_ATLAS_GLYPH_FILL_RULE);
         if (attribs.config.errorCorrection.mode != msdfgen::ErrorCorrectionConfig::DISABLED) {
             config.errorCorrection.mode = attribs.config.errorCorrection.mode;
             config.errorCorrection.distanceCheckMode = msdfgen::ErrorCorrectionConfig::DO_NOT_CHECK_DISTANCE;
diff --git a/msdf-atlas-gen/main.cpp b/msdf-atlas-gen/main.cpp
@@ -1,9 +1,9 @@
 
 /*
-* MULTI-CHANNEL SIGNED DISTANCE FIELD ATLAS GENERATOR - standalone console program
-* --------------------------------------------------------------------------------
-* A utility by Viktor Chlumsky, (c) 2020 - 2025
-*/
+ * MULTI-CHANNEL SIGNED DISTANCE FIELD ATLAS GENERATOR - standalone console program
+ * --------------------------------------------------------------------------------
+ * A utility by Viktor Chlumsky, (c) 2020 - 2026
+ */
 
 #ifdef MSDF_ATLAS_STANDALONE
 
diff --git a/msdf-atlas-gen/msdf-atlas-gen.h b/msdf-atlas-gen/msdf-atlas-gen.h
@@ -4,7 +4,7 @@
 /*
  * MULTI-CHANNEL SIGNED DISTANCE FIELD ATLAS GENERATOR
  * ---------------------------------------------------
- * A utility by Viktor Chlumsky, (c) 2020 - 2025
+ * A utility by Viktor Chlumsky, (c) 2020 - 2026
  * Generates compact bitmap font atlases using MSDFgen
  */
 
diff --git a/vcpkg.json b/vcpkg.json
@@ -1,7 +1,7 @@
 {
     "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/master/docs/vcpkg.schema.json",
     "name": "msdf-atlas-gen",
-    "version": "1.3.0",
+    "version": "1.4.0",
     "description": "Multi-channel signed distance field atlas generator",
     "homepage": "https://github.com/Chlumsky/msdf-atlas-gen",
     "license": "MIT",

Original file line number	Diff line number	Diff line change
`@@ -20,10 +20,10 @@ bool Workload::finishSequential() {`
`20`	`20`	`}`
`21`	`21`
`22`	`22`	`bool Workload::finishParallel(int threadCount) {`
`23`		`- bool result = true;`
	`23`	`+ std::atomic<bool> result(true);`
`24`	`24`	`std::atomic<int> next(0);`
`25`	`25`	`std::function<void(int)> threadWorker = [this, &result, &next](int threadNo) {`
`26`		`- for (int i = next++; result && i < chunks; i = next++) {`
	`26`	`+ for (int i = next++; i < chunks && result; i = next++) {`
`27`	`27`	`if (!workerFunction(i, threadNo))`
`28`	`28`	`result = false;`
`29`	`29`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,7 +1,7 @@`
`1`	`1`	`{`
`2`	`2`	`"$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/master/docs/vcpkg.schema.json",`
`3`	`3`	`"name": "msdf-atlas-gen",`
`4`		`- "version": "1.3.0",`
	`4`	`+ "version": "1.4.0",`
`5`	`5`	`"description": "Multi-channel signed distance field atlas generator",`
`6`	`6`	`"homepage": "https://github.com/Chlumsky/msdf-atlas-gen",`
`7`	`7`	`"license": "MIT",`