From 5bcc3d5d6dbc5c4115686ce62651d95a4dcaf0b7 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Mon, 10 Jan 2022 17:04:31 -0500
Subject: [PATCH] absolute C64 filter macros!

exclusive to .fur format
---
 src/engine/platform/c64.cpp | 10 +++++++---
 src/gui/gui.cpp             | 16 ++++++++++++----
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/engine/platform/c64.cpp b/src/engine/platform/c64.cpp
index 619ee92c..3d78a5dc 100644
--- a/src/engine/platform/c64.cpp
+++ b/src/engine/platform/c64.cpp
@@ -26,9 +26,13 @@ void DivPlatformC64::tick() {
     if (chan[i].std.hadVol) {
       DivInstrument* ins=parent->getIns(chan[i].ins);
       if (ins->c64.volIsCutoff) {
-        filtCut-=((signed char)chan[i].std.vol-18)*7;
-        if (filtCut>2047) filtCut=2047;
-        if (filtCut<0) filtCut=0;
+        if (ins->c64.filterIsAbs) {
+          filtCut=chan[i].std.vol;
+        } else {
+          filtCut-=((signed char)chan[i].std.vol-18)*7;
+          if (filtCut>2047) filtCut=2047;
+          if (filtCut<0) filtCut=0;
+        }
         updateFilter();
       } else {
         vol=chan[i].std.vol;
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index f3da2868..8f801b68 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -751,7 +751,11 @@ void FurnaceGUI::drawInsEdit() {
           // volume macro
           ImGui::Separator();
           if (ins->type==DIV_INS_C64 && ins->c64.volIsCutoff) {
-            ImGui::Text("Relative Cutoff Macro");
+            if (ins->c64.filterIsAbs) {
+              ImGui::Text("Absolute Cutoff Macro");
+            } else {
+              ImGui::Text("Relative Cutoff Macro");
+            }
           } else {
             ImGui::Text("Volume Macro");
             ImGui::SameLine();
@@ -770,7 +774,7 @@ void FurnaceGUI::drawInsEdit() {
             }
           }
           for (int i=0; i<ins->std.volMacroLen; i++) {
-            if (ins->type==DIV_INS_C64 && ins->c64.volIsCutoff) {
+            if (ins->type==DIV_INS_C64 && ins->c64.volIsCutoff && !ins->c64.filterIsAbs) {
               asFloat[i]=ins->std.volMacro[i]-18;
             } else {
               asFloat[i]=ins->std.volMacro[i];
@@ -782,8 +786,12 @@ void FurnaceGUI::drawInsEdit() {
           int volMin=0;
           if (ins->type==DIV_INS_C64) {
             if (ins->c64.volIsCutoff) {
-              volMin=-18;
-              volMax=18;
+              if (ins->c64.filterIsAbs) {
+                volMax=2047;
+              } else {
+                volMin=-18;
+                volMax=18;
+              }
             }
           }
           ImGui::PlotHistogram("##IVolMacro",asFloat,ins->std.volMacroLen,0,NULL,volMin,volMax,ImVec2(400.0f*dpiScale,200.0f*dpiScale));