GUI: prepare for FM preview

CMakeLists.txt

@@ -624,6 +624,7 @@ src/gui/editing.cpp
 src/gui/editControls.cpp
 src/gui/effectList.cpp
 src/gui/findReplace.cpp
+src/gui/fmPreview.cpp
 src/gui/gradient.cpp
 src/gui/grooves.cpp
 src/gui/insEdit.cpp

src/gui/debugWindow.cpp

@@ -519,6 +519,18 @@ void FurnaceGUI::drawDebug() {
       ImGui::InputFloat("maxRr",&maxRr);
       ImGui::TreePop();
     }
+    if (ImGui::TreeNode("FM Preview")) {
+      if (ImGui::Button("Generate")) {
+        DivInstrument* ins=e->getIns(curIns);
+        if (ins!=NULL) renderFMPreview(ins->fm);
+      }
+      float asFloat[FM_PREVIEW_SIZE];
+      for (int i=0; i<FM_PREVIEW_SIZE; i++) {
+        asFloat[i]=(float)fmPreview[i]/8192.0f;
+      }
+      ImGui::PlotLines("##DebugFMPreview",asFloat,FM_PREVIEW_SIZE,0,"Preview",-1.0,1.0,ImVec2(300.0f*dpiScale,150.0f*dpiScale));
+      ImGui::TreePop();
+    }
     if (ImGui::TreeNode("User Interface")) {
       if (ImGui::Button("Inspect")) {
         inspectorOpen=!inspectorOpen;

src/gui/fmPreview.cpp

@@ -0,0 +1,84 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2023 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _USE_MATH_DEFINES
+#include "gui.h"
+#include "../../extern/opn/ym3438.h"
+
+#define FM_WRITE(addr,val) \
+  OPN2_Write(&fm,0,(addr)); \
+  do { \
+    OPN2_Clock(&fm,out); \
+  } while (fm.write_busy); \
+  OPN2_Write(&fm,1,(val)); \
+  do { \
+    OPN2_Clock(&fm,out); \
+  } while (fm.write_busy); \
+
+void FurnaceGUI::renderFMPreview(const DivInstrumentFM& params, int pos) {
+  ym3438_t fm;
+  short out[2];
+  int aOut=0;
+
+  OPN2_Reset(&fm); 
+  OPN2_SetChipType(&fm,ym3438_mode_opn);
+
+  // set params
+  FM_WRITE(0x50,31); // AR
+  FM_WRITE(0x54,31);
+  FM_WRITE(0x58,31);
+  FM_WRITE(0x5c,31);
+  FM_WRITE(0x60,0); // DR
+  FM_WRITE(0x64,0);
+  FM_WRITE(0x68,0);
+  FM_WRITE(0x6c,0);
+  FM_WRITE(0x70,0); // D2R
+  FM_WRITE(0x74,0);
+  FM_WRITE(0x78,0);
+  FM_WRITE(0x7c,0);
+  FM_WRITE(0x80,0); // SL/RR
+  FM_WRITE(0x84,0);
+  FM_WRITE(0x88,0);
+  FM_WRITE(0x8c,0);
+  FM_WRITE(0xa4,0x0c); // frequency
+  FM_WRITE(0xa0,0);
+  FM_WRITE(0xb0,(params.alg&7)|((params.fb&7)<<3)); // ALG/FB
+  FM_WRITE(0xb4,0xc0); // pan
+  FM_WRITE(0x30,params.op[0].mult&15); // MULT
+  FM_WRITE(0x34,params.op[1].mult&15);
+  FM_WRITE(0x38,params.op[2].mult&15);
+  FM_WRITE(0x3c,params.op[3].mult&15);
+  FM_WRITE(0x40,params.op[0].tl&127); // TL
+  FM_WRITE(0x44,params.op[1].tl&127);
+  FM_WRITE(0x48,params.op[2].tl&127);
+  FM_WRITE(0x4c,params.op[3].tl&127);
+  FM_WRITE(0x28,0xf0); // key on
+
+  // render
+  for (int i=0; i<FM_PREVIEW_SIZE; i++) {
+    aOut=0;
+    for (int j=0; j<24; j++) {
+      OPN2_Clock(&fm,out);
+    }
+    aOut+=fm.ch_out[0];
+    if (aOut<-32768) aOut=-32768;
+    if (aOut>32767) aOut=32767;
+    fmPreview[i]=aOut;
+  }
+}

src/gui/gui.h

@@ -68,6 +68,8 @@
 
 #define BIND_FOR(x) getKeyName(actionKeys[x],true).c_str()
 
+#define FM_PREVIEW_SIZE 1024
+
 // TODO:
 // - add colors for FM envelope and waveform
 // - maybe add "alternate" color for FM modulators/carriers (a bit difficult)
@@ -1192,6 +1194,7 @@ class FurnaceGUI {
   ImVec2 mobileEditButtonPos, mobileEditButtonSize;
   const int* curSysSection;
   DivInstrumentFM opllPreview;
+  short fmPreview[FM_PREVIEW_SIZE];
 
   String pendingRawSample;
   int pendingRawSampleDepth, pendingRawSampleChannels;
@@ -1887,6 +1890,7 @@ class FurnaceGUI {
   void drawGBEnv(unsigned char vol, unsigned char len, unsigned char sLen, bool dir, const ImVec2& size);
   bool drawSysConf(int chan, DivSystem type, DivConfig& flags, bool modifyOnChange);
   void kvsConfig(DivInstrument* ins);
+  void renderFMPreview(const DivInstrumentFM& params, int pos=0);
 
   // these ones offer ctrl-wheel fine value changes.
   bool CWSliderScalar(const char* label, ImGuiDataType data_type, void* p_data, const void* p_min, const void* p_max, const char* format=NULL, ImGuiSliderFlags flags=0);