# HG changeset patch
# User sam <sam@basx.dev>
# Date 1735728771 -25200
# Node ID 5bbcd40eb145f1c00bfb96ed23e8b330ff60488b
# Parent  23b4d8c84501dde8dd2ce68391a58b627fe49f6d
did: fix overlapping glyph-quads (again)

diff -r 23b4d8c84501 -r 5bbcd40eb145 semicongine/text.nim
--- a/semicongine/text.nim	Wed Jan 01 16:38:27 2025 +0700
+++ b/semicongine/text.nim	Wed Jan 01 17:52:51 2025 +0700
@@ -54,7 +54,8 @@
     glyphquads.pos[glyphIndex][i_y[vertexI]] * scale,
     0
   );
-  gl_Position = vec4(vertexPos + position, 1.0);
+  // the epsilon-offset is necessary, as otherwise characters with the same Z might overlap, despite transparency
+  gl_Position = vec4(vertexPos + position - vec3(0, 0, clamp(0, 1, gl_InstanceIndex * epsilon)), 1.0);
   vec2 uv = vec2(glyphquads.uv[glyphIndex][i_x[vertexI]], glyphquads.uv[glyphIndex][i_y[vertexI]]);
   fragmentUv = uv;
   fragmentColor = color;