diff --git a/data/ofxMsdfgen/shaders/simple/ES2/shader.frag b/data/ofxMsdfgen/shaders/simple/ES2/shader.frag
index d509ed2..e6fe164 100644
--- a/data/ofxMsdfgen/shaders/simple/ES2/shader.frag
+++ b/data/ofxMsdfgen/shaders/simple/ES2/shader.frag
@@ -1,12 +1,10 @@
 precision highp float;
 
 // these are our textures
-uniform sampler2D msdf_0;
-uniform sampler2D msdf_1;
+uniform sampler2D msdf;
 
 uniform vec4 fontColor;
-uniform float msdf_mix;
-uniform float msdf_pxratio;
+uniform float pxRange;
 
 // this comes from the vertex shader
 varying vec2 texCoordVarying;
@@ -15,8 +13,10 @@ float median(float r, float g, float b) {
     return max(min(r, g), min(max(r, g), b));
 }
 
-float screenPxRange(float ratio) {
-    return ratio * 2.0;
+float screenPxRange() {
+    vec2 unitRange = vec2(pxRange)/vec2(textureSize(msdf));
+    vec2 screenTexSize = vec2(1.0)/fwidth(texCoordVarying);
+    return max(0.5*dot(unitRange, screenTexSize), 1.0);
 }
 
 void main()
@@ -24,11 +24,9 @@ void main()
     vec4 bgColor = vec4(fontColor.rgb,0);
     vec4 fgColor = fontColor;
 
-    vec3 msd_0 = texture2D(msdf_0, texCoordVarying).rgb;
-    vec3 msd_1 = texture2D(msdf_1, texCoordVarying).rgb;
-    vec3 msd = mix(msd_0, msd_1,msdf_mix);
-    float sd = median(msd.r, msd.g, msd.b);
-    float screenPxDistance = screenPxRange(msdf_pxratio)*(sd - 0.5);
+    vec3 msdf_rgb = texture2D(msdf, texCoordVarying).rgb;
+    float sd = median(msdf_rgb.r, msdf_rgb.g, msdf_rgb.b);
+    float screenPxDistance = screenPxRange()*(sd - 0.5);
     float opacity = clamp(screenPxDistance + 0.5, 0.0, 1.0);
     gl_FragColor = mix(bgColor, fgColor, opacity);
 }
diff --git a/data/ofxMsdfgen/shaders/simple/GL2/shader.frag b/data/ofxMsdfgen/shaders/simple/GL2/shader.frag
index 2226d46..0ecf284 100644
--- a/data/ofxMsdfgen/shaders/simple/GL2/shader.frag
+++ b/data/ofxMsdfgen/shaders/simple/GL2/shader.frag
@@ -3,11 +3,9 @@ precision highp float;
 
 // these are our textures
 uniform sampler2DRect msdf_0;
-uniform sampler2DRect msdf_1;
 
 uniform vec4 fontColor;
-uniform float msdf_mix;
-uniform float msdf_pxratio;
+uniform float pxRange;
 
 // this comes from the vertex shader
 varying vec2 texCoordVarying;
@@ -17,7 +15,9 @@ float median(float r, float g, float b) {
 }
 
 float screenPxRange() {
-    return 2.0;
+    vec2 unitRange = vec2(pxRange)/vec2(textureSize(msdf));
+    vec2 screenTexSize = vec2(1.0)/fwidth(texCoordVarying);
+    return max(0.5*dot(unitRange, screenTexSize), 1.0);
 }
 
 void main()
@@ -25,10 +25,8 @@ void main()
     vec4 bgColor = vec4(fontColor.rgb,0);
     vec4 fgColor = fontColor;
 
-    vec3 msd_0 = texture2DRect(msdf_0, texCoordVarying).rgb;
-    vec3 msd_1 = texture2DRect(msdf_1, texCoordVarying).rgb;
-    vec3 msd = mix(msd_0, msd_1,msdf_mix);
-    float sd = median(msd.r, msd.g, msd.b);
+    vec3 msdf_rgb = texture2DRect(msdf, texCoordVarying).rgb;
+    float sd = median(msdf_rgb.r, msdf_rgb.g, msdf_rgb.b);
     float screenPxDistance = screenPxRange()*(sd - 0.5);
     float opacity = clamp(screenPxDistance + 0.5, 0.0, 1.0);
     gl_FragColor = mix(bgColor, fgColor, opacity);