chrome letters first attempt

[vrfileman] / sdr / dfont.p.glsl

diff --git a/sdr/dfont.p.glsl b/sdr/dfont.p.glsl
index 890b4ef..cf60f27 100644 (file)
--- a/sdr/dfont.p.glsl
+++ b/sdr/dfont.p.glsl
@@ -1,5 +1,12 @@
 uniform sampler2D tex;
 uniform float smoothness;
+uniform float height;
+
+varying vec2 local_pt;
+
+void gradcurves(float t, out float over, out float under);
+
+#define HALF_PI 1.570796326794897
 
 void main()
 {
@@ -15,9 +22,32 @@ void main()
        float glyph = smoothstep(0.47 - smoothness, 0.47 + smoothness, dist);
        float outline = smoothstep(0.54 - smoothness, 0.54 + smoothness, dist);
 
-       float beveldot = max(dot(grad, normalize(vec2(1.0, 1.0))), 0.0);
-       vec3 bevelcol = mix(vec3(0.05, 0.1, 0.6), vec3(1.0, 0.2, 0.8), beveldot);
+       // --- face gradients ---
+       float t = local_pt.y / height;
+
+       float c_over, c_under;
+       float tlow = min(2.0 * t, 1.0);
+       gradcurves(tlow, c_over, c_under);
+       vec3 color_low = vec3(c_over, c_under, c_over);
+
+       float thigh = max(2.0 * t - 1.0, 0.0);
+       gradcurves(thigh, c_over, c_under);
+       vec3 color_high = vec3(c_under, c_under, c_over);
+
+       vec3 color = mix(color_low, color_high, step(0.5, t));
 
-       gl_FragColor.rgb = mix(bevelcol, vec3(1.0), outline);
+       // --- bevel gradients ---
+       float bv_shade = mod(1.0 * dot(grad, normalize(vec2(1.0, 1.0))) * 0.5 + 0.5, 1.0);
+
+       gradcurves(1.0 - bv_shade, c_over, c_under);
+       vec3 bv_col = vec3(c_under, c_under, c_over);
+
+       gl_FragColor.rgb = mix(bv_col, color, outline);
        gl_FragColor.a = glyph;
 }
+
+void gradcurves(float t, out float over, out float under)
+{
+       over = cos(t * HALF_PI);
+       under = cos(t * HALF_PI + HALF_PI) + 1.0;
+}