diff --git a/src/gui/render/renderGL.cpp b/src/gui/render/renderGL.cpp
index 1349c919e..ac26561e7 100644
--- a/src/gui/render/renderGL.cpp
+++ b/src/gui/render/renderGL.cpp
@@ -163,36 +163,35 @@ const char* sh_oscRender_srcF=
   "uniform vec4 uColor;\n"
   "uniform vec2 uResolution;\n"
   "uniform float uLineWidth;\n"
-  "uniform float uAdvance;\n"
   "uniform sampler1D oscVal;\n"
   "in vec2 fur_fragCoord;\n"
   "out vec4 fur_FragColor;\n"
   "void main() {\n"
-  "  vec2 uv=fur_fragCoord/uResolution;\n"
-  "  uv.y*=2.0;\n"
   "  float alpha=0.0;\n"
-  "  float xMax=uv.x+uAdvance*uLineWidth;\n"
+  "  float xMax=ceil(fur_fragCoord.x+uLineWidth);\n"
+  "  float oneStep=1.0/2048.0;\n"
   "  float valmax=-1024.0;\n"
   "  float valmin=1024.0;\n"
-
-  "  for (float x=uv.x-uAdvance*uLineWidth; x<=xMax; x+=uAdvance) {\n"
-  "    float val=texture(oscVal,x).x;\n"
+  "  for (float x=floor(fur_fragCoord.x-uLineWidth); x<=xMax; x+=1.0) {\n"
+  "    float val=texture(oscVal,x*oneStep).x;\n"
   "    if (val>valmax) valmax=val;\n"
   "    if (val<valmin) valmin=val;\n"
   "  }\n"
-  //"  if ((fur_fragCoord.y-uLineWidth)>valmax*uResolution.y*0.5) discard;\n"
-  //"  if ((fur_fragCoord.y+uLineWidth)<valmin*uResolution.y*0.5) discard;\n"
-  "  float slope=abs(valmax-valmin)*uResolution.y*0.5;\n"
-  "  float slopeDiv=min(uAdvance,(uAdvance/slope));\n"
-  "  float xRight=uv.x+((uLineWidth)/uResolution.x);\n"
-  "  for (float x=max(0.0,uv.x-(uLineWidth/uResolution.x)); x<=xRight; x+=slopeDiv) {\n"
-  "    float val=texture(oscVal,x).x*uResolution.y*0.5;\n"
-  "    alpha+=clamp(uLineWidth-distance(vec2(fur_fragCoord.x,fur_fragCoord.y),vec2(x*uResolution.x,val)),0.0,1000.0);\n"
+  "  if ((fur_fragCoord.y-uLineWidth)>valmax*uResolution.y) discard;\n"
+  "  if ((fur_fragCoord.y+uLineWidth)<valmin*uResolution.y) discard;\n"
+  "  float slope=sqrt(abs(valmax-valmin)*uResolution.y);\n"
+  "  float slopeDiv=min(1.0,1.0/ceil(slope));\n"
+  "  float xRight=ceil(fur_fragCoord.x+uLineWidth);\n"
+  "  for (float x=max(0.0,floor(fur_fragCoord.x-uLineWidth)); x<=xRight; x+=slopeDiv) {\n"
+  "    float val0=texture(oscVal,floor(x)*oneStep).x*uResolution.y;\n"
+  "    float val1=texture(oscVal,floor(x+1.0)*oneStep).x*uResolution.y;\n"
+  "    float val=mix(val0,val1,fract(x));\n"
+  "    alpha+=clamp(uLineWidth-distance(vec2(fur_fragCoord.x,fur_fragCoord.y),vec2(x,val)),0.0,1.0);\n"
   "  }\n"
   "  if (slope>1.0) {\n"
-  "    fur_FragColor = vec4(uColor.xyz,uColor.w*clamp(alpha*0.125,0.0,1.0));\n"
+  "    fur_FragColor = vec4(uColor.xyz,uColor.w*clamp(alpha/uLineWidth,0.0,1.0));\n"
   "  } else {\n"
-  "    fur_FragColor = vec4(uColor.xyz,uColor.w*clamp(alpha*0.125,0.0,1.0));\n"
+  "    fur_FragColor = vec4(uColor.xyz,uColor.w*clamp(alpha/uLineWidth,0.0,1.0));\n"
   "  }\n"
   "}\n";
 #endif