get curves data in shader

data/ofxGPUFont/shaders/GL3/font.frag

@@ -20,7 +20,7 @@ uniform vec4 color;
 // Size of the window (in pixels) used for 1-dimensional anti-aliasing along each rays.
 //   0 - no anti-aliasing
 //   1 - normal anti-aliasing
-// >=2 - exaggerated effect 
+// >=2 - exaggerated effect
 uniform float antiAliasingWindowSize = 1.0;
 
 // Enable a second ray along the y-axis to achieve 2-dimensional anti-aliasing.
@@ -65,7 +65,7 @@ float computeCoverage(float inverseDiameter, vec2 p0, vec2 p1, vec2 p2) {
 		// Quadratic segment, solve abc formula to find roots.
 		float radicand = b.y*b.y - a.y*c.y;
 		if (radicand <= 0) return 0.0;
-	
+
 		float s = sqrt(radicand);
 		t0 = (b.y - s) / a.y;
 		t1 = (b.y + s) / a.y;
@@ -86,7 +86,7 @@ float computeCoverage(float inverseDiameter, vec2 p0, vec2 p1, vec2 p2) {
 	}
 
 	float alpha = 0;
-	
+
 	if (t0 >= 0 && t0 < 1) {
 		float x = (a.x*t0 - 2.0*b.x)*t0 + c.x;
 		alpha += clamp(x * inverseDiameter + 0.5, 0, 1);
@@ -123,6 +123,10 @@ void main() {
 			alpha += computeCoverage(inverseDiameter.y, rotate(p0), rotate(p1), rotate(p2));
 		}
 	}
+    vec4 debug = texelFetch(curves, int(uv.x * textureSize(curves)));
+    result = vec4(debug.rgb, 1.0);
+
+    return;
 
 	if (enableSuperSamplingAntiAliasing) {
 		alpha *= 0.5;