diff --git a/src/gui/debugWindow.cpp b/src/gui/debugWindow.cpp
index 2e6412d02..98a2d9dc7 100644
--- a/src/gui/debugWindow.cpp
+++ b/src/gui/debugWindow.cpp
@@ -23,7 +23,26 @@
 #include "IconsFontAwesome4.h"
 #include <SDL_timer.h>
 #include <fmt/printf.h>
-#include <imgui.h>
+#include "imgui.h"
+#include "imgui_internal.h"
+
+PendingDrawOsc _debugDo;
+static float oscDebugData[2048];
+static int oscDebugLen=800;
+static int oscDebugHeight=400;
+static float oscDebugLineSize=1.0;
+static float oscDebugMin=-1.0;
+static float oscDebugMax=1.0;
+static float oscDebugPower=1.0;
+static int oscDebugRepeat=1;
+
+static void _drawOsc(const ImDrawList* drawList, const ImDrawCmd* cmd) {
+  if (cmd!=NULL) {
+    if (cmd->UserCallbackData!=NULL) {
+      ((FurnaceGUI*)(((PendingDrawOsc*)cmd->UserCallbackData)->gui))->runPendingDrawOsc((PendingDrawOsc*)cmd->UserCallbackData);
+    }
+  }
+}
 
 void FurnaceGUI::drawDebug() {
   static int bpOrder;
@@ -591,6 +610,56 @@ void FurnaceGUI::drawDebug() {
       ImGui::Unindent();
       ImGui::TreePop();
     }
+    if (ImGui::TreeNode("Osc Render Test")) {
+      ImGui::InputInt("Length",&oscDebugLen);
+      ImGui::InputInt("Height",&oscDebugHeight);
+      ImGui::InputFloat("Line Size",&oscDebugLineSize);
+      ImGui::InputFloat("Min",&oscDebugMin);
+      ImGui::InputFloat("Max",&oscDebugMax);
+      ImGui::InputFloat("Power",&oscDebugPower);
+      ImGui::InputInt("Repeat",&oscDebugRepeat);
+
+      if (oscDebugLen<1) oscDebugLen=1;
+      if (oscDebugLen>2048) oscDebugLen=2048;
+
+      if (oscDebugHeight<1) oscDebugHeight=1;
+      if (oscDebugHeight>2048) oscDebugHeight=2048;
+
+      memset(oscDebugData,0,2048*sizeof(float));
+      for (int i=0; i<oscDebugLen; i++) {
+        oscDebugData[i]=oscDebugMin+(oscDebugMax-oscDebugMin)*pow((float)((i*oscDebugRepeat)%oscDebugLen)/(float)oscDebugLen,oscDebugPower);
+      }
+      
+      if (rend->supportsDrawOsc()) {
+        ImDrawList* dl=ImGui::GetWindowDrawList();
+        ImGuiWindow* window=ImGui::GetCurrentWindow();
+
+        ImVec2 size=ImVec2(oscDebugLen,oscDebugHeight);
+        ImVec2 minArea=window->DC.CursorPos;
+        ImVec2 maxArea=ImVec2(
+          minArea.x+size.x,
+          minArea.y+size.y
+        );
+        ImRect rect=ImRect(minArea,maxArea);
+        ImGuiStyle& style=ImGui::GetStyle();
+        ImGui::ItemSize(size,style.FramePadding.y);
+        if (ImGui::ItemAdd(rect,ImGui::GetID("debugOsc"))) {
+          _debugDo.gui=this;
+          _debugDo.data=oscDebugData;
+          _debugDo.len=oscDebugLen;
+          _debugDo.pos0=rect.Min;
+          _debugDo.pos1=rect.Max;
+          _debugDo.color=ImVec4(1.0,1.0,1.0,1.0);
+          _debugDo.lineSize=dpiScale*oscDebugLineSize;
+
+          dl->AddCallback(_drawOsc,&_debugDo);
+          dl->AddCallback(ImDrawCallback_ResetRenderState,NULL);
+        }
+      } else {
+        ImGui::Text("Render Backend does not support osc rendering.");
+      }
+      ImGui::TreePop();
+    }
     if (ImGui::TreeNode("User Interface")) {
       if (ImGui::Button("Inspect")) {
         inspectorOpen=!inspectorOpen;
diff --git a/src/gui/render/renderGL.cpp b/src/gui/render/renderGL.cpp
index c8660ebde..a830fd975 100644
--- a/src/gui/render/renderGL.cpp
+++ b/src/gui/render/renderGL.cpp
@@ -116,7 +116,7 @@ const char* sh_oscRender_srcF=
   "  }\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 slope=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"
@@ -605,13 +605,13 @@ bool FurnaceGUIRenderGL::init(SDL_Window* win) {
   C(glGenTextures(1,&oscDataTex));
 #ifdef USE_GLES
   C(glBindTexture(GL_TEXTURE_2D,oscDataTex));
-  C(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR));
-  C(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR));
+  C(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST));
+  C(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST));
   C(glTexImage2D(GL_TEXTURE_2D,0,GL_RED_EXT,2048,1,0,GL_RED_EXT,GL_FLOAT,NULL));
 #else
   C(glBindTexture(GL_TEXTURE_1D,oscDataTex));
-  C(glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_MIN_FILTER,GL_LINEAR));
-  C(glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_MAG_FILTER,GL_LINEAR));
+  C(glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_MIN_FILTER,GL_NEAREST));
+  C(glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_MAG_FILTER,GL_NEAREST));
   C(glTexImage1D(GL_TEXTURE_1D,0,GL_RED,2048,0,GL_RED,GL_FLOAT,NULL));
 #endif
   C(furActiveTexture(GL_TEXTURE0));