1 files changed, 44 insertions, 0 deletions
diff --git a/src/Runtime/res/effectlib/distancefieldtext_core.vert b/src/Runtime/res/effectlib/distancefieldtext_core.vert
new file mode 100644
index 00000000..074a73ac
--- /dev/null
+++ b/src/Runtime/res/effectlib/distancefieldtext_core.vert
@@ -0,0 +1,44 @@
+in vec3 vCoord;
+in vec2 tCoord;
+
+out vec2 sampleCoord;
+
+out vec2 alphas;
+
+uniform mat4 mvp;
+uniform mat4 modelView;
+uniform int textureWidth;
+uniform int textureHeight;
+uniform float fontScale;
+
+float thresholdFunc(float scale)
+{
+    float base = 0.5;
+    float baseDev = 0.065;
+    float devScaleMin = 0.15;
+    float devScaleMax = 0.3;
+    return base - ((clamp(scale, devScaleMin, devScaleMax) - devScaleMin)
+                   / (devScaleMax - devScaleMin) * -baseDev + baseDev);
+}
+
+float spreadFunc(float scale)
+{
+    return 0.06 / scale;
+}
+
+vec2 alphaRange(float scale)
+{
+    float base = thresholdFunc(scale);
+    float range = spreadFunc(scale);
+    float alphaMin = max(0.0, base - range);
+    float alphaMax = min(base + range, 1.0);
+    return vec2(alphaMin, alphaMax);
+}
+
+void main()
+{
+     float scale = fontScale * sqrt(abs(determinant(modelView)));
+     alphas = alphaRange(scale);
+     sampleCoord = tCoord * vec2(1.0 / textureWidth, 1.0 / textureHeight);
+     gl_Position = mvp * vec4(vCoord, 1.0);
+}