"Decouple CMS and OPL emulations" - dosbox-staging

CHANGELOG

@@ -95,6 +95,7 @@ NEXT
     - remove few rendundant labels, adjust names of some others
     - retain 'show advanced options' state throughout session
   - SVN r4483: Fix compilation in Visual Studio 2008. (Allofich)
+  - DOSBox Staging: Decouple CMS and OPL emulations (Allofich)
 
 2024.07.01
   - Correct Hercules InColor memory emulation. Read and write planar

include/hardware.h

@@ -22,7 +22,7 @@
 
 class Section;
 enum OPL_Mode {
-	OPL_none,OPL_cms,OPL_opl2,OPL_dualopl2,OPL_opl3,OPL_opl3gold,OPL_hardware,OPL_hardwareCMS,OPL_esfm
+	OPL_none,OPL_opl2,OPL_dualopl2,OPL_opl3,OPL_opl3gold,OPL_hardware,OPL_hardwareCMS,OPL_esfm
 };
 #define CAPTURE_WAVE	0x01
 #define CAPTURE_OPL		0x02
@@ -36,8 +36,9 @@ enum OPL_Mode {
 extern Bitu CaptureState;
 
 void OPL_Init(Section* sec,OPL_Mode oplmode);
-void CMS_Init(Section* sec);
 void OPL_ShutDown(Section* sec);
+
+void CMS_Init(Section* sec);
 void CMS_ShutDown(Section* sec);
 
 bool SB_Get_Address(Bitu& sbaddr, Bitu& sbirq, Bitu& sbdma);

src/dosbox.cpp

@@ -1392,7 +1392,8 @@ void DOSBOX_SetupConfigSections(void) {
     const char *mt32reverbLevels[] = {"0", "1", "2", "3", "4", "5", "6", "7", nullptr};
     const char* gustypes[] = { "classic", "classic37", "max", "interwave", nullptr };
     const char* sbtypes[] = { "sb1", "sb2", "sbpro1", "sbpro2", "sb16", "sb16vibra", "gb", "ess688", "ess1688", "reveal_sc400", "none", nullptr };
-    const char* oplmodes[]={ "auto", "cms", "opl2", "dualopl2", "opl3", "opl3gold", "none", "hardware", "hardwaregb", "esfm", nullptr };
+    const char* cms_settings[] = { "on", "off", "auto", nullptr };
+    const char* oplmodes[] = { "auto", "opl2", "dualopl2", "opl3", "opl3gold", "none", "hardware", "hardwaregb", "esfm", nullptr };
     const char* serials[] = { "dummy", "disabled", "modem", "nullmodem", "serialmouse", "directserial", "log", "file", nullptr };
     const char* acpi_rsd_ptr_settings[] = { "auto", "bios", "ebda", nullptr };
     const char* cpm_compat_modes[] = { "auto", "off", "msdos2", "msdos5", "direct", nullptr };
@@ -3669,10 +3670,18 @@ void DOSBOX_SetupConfigSections(void) {
     Pbool->Set_help("Allow the Sound Blaster mixer to modify the DOSBox-X mixer.");
     Pbool->SetBasic(true);
 
+    Pstring = secprop->Add_string("cms", Property::Changeable::WhenIdle, "auto");
+    Pstring->Set_values(cms_settings);
+    Pstring->Set_help(
+        "Enable CMS emulation ('auto' by default).\n"
+        "  off:   Disable CMS emulation (except when the Game Blaster is selected).\n"
+        "  on:    Enable CMS emulation on Sound Blaster 1 and 2.\n"
+        "  auto:  Auto-enable CMS emulation for Sound Blaster 1 and Game Blaster.");
+
     Pstring = secprop->Add_string("oplmode",Property::Changeable::WhenIdle,"auto");
     Pstring->Set_values(oplmodes);
     Pstring->Set_help("Type of OPL emulation. On 'auto' the mode is determined by the 'sbtype' setting.\n"
-			"All OPL modes are AdLib-compatible, except for 'cms' (set 'sbtype=none' with 'cms' for a Game Blaster).");
+            "All OPL modes are AdLib-compatible.");
     Pstring->SetBasic(true);
 
     Pbool = secprop->Add_bool("adlib force timer overflow on detect",Property::Changeable::WhenIdle,false);

src/hardware/adlib.cpp

@@ -1544,7 +1544,6 @@ OPL_Mode Module::oplmode=OPL_none;
 
 std::string getoplmode() {
     if (Adlib::Module::oplmode == OPL_none) return "None";
-    else if (Adlib::Module::oplmode == OPL_cms) return "CMS";
     else if (Adlib::Module::oplmode == OPL_opl2) return "OPL2";
     else if (Adlib::Module::oplmode == OPL_dualopl2) return "Dual OPL2";
     else if (Adlib::Module::oplmode == OPL_opl3) return "OPL3";

src/hardware/sblaster.cpp

@@ -174,6 +174,7 @@ struct SB_INFO {
     bool busy_cycle_always;
     bool ess_playback_mode;
     bool no_filtering;
+    bool cms;
     uint8_t sc400_cfg;
     uint8_t time_constant;
     uint8_t sc400_dsp_major,sc400_dsp_minor;
@@ -3718,7 +3719,7 @@ class SBLASTER: public Module_base {
         /* OPL/CMS Init */
         const char * omode=config->Get_string("oplmode");
         if (!strcasecmp(omode,"none")) opl_mode=OPL_none;
-        else if (!strcasecmp(omode,"cms")) opl_mode=OPL_cms;
+        else if (!strcasecmp(omode,"cms")); // Skip for backward compatibility with existing configurations
         else if (!strcasecmp(omode,"opl2")) opl_mode=OPL_opl2;
         else if (!strcasecmp(omode,"dualopl2")) opl_mode=OPL_dualopl2;
         else if (!strcasecmp(omode,"opl3")) opl_mode=OPL_opl3;
@@ -3730,10 +3731,8 @@ class SBLASTER: public Module_base {
         else {
             switch (type) {
             case SBT_NONE:
-                opl_mode=OPL_none;
-                break;
             case SBT_GB:
-                opl_mode=OPL_cms;
+                opl_mode=OPL_none;
                 break;
             case SBT_1:
             case SBT_2:
@@ -3929,15 +3928,7 @@ class SBLASTER: public Module_base {
             if (!IS_PC98_ARCH)
                 WriteHandler[0].Install(0x388,adlib_gusforward,IO_MB);
             break;
-        case OPL_cms:
-            assert(!IS_PC98_ARCH);
-            WriteHandler[0].Install(0x388,adlib_gusforward,IO_MB);
-            CMS_Init(section);
-            break;
         case OPL_opl2:
-            assert(!IS_PC98_ARCH);
-            CMS_Init(section);
-            // fall-through
         case OPL_dualopl2:
             assert(!IS_PC98_ARCH);
             // fall-through
@@ -3962,6 +3953,47 @@ class SBLASTER: public Module_base {
 #endif
             break;
         }
+
+        // Backward compatibility with existing configurations
+        if(section->Get_string("oplmode") == "cms") {
+            LOG(LOG_SB, LOG_WARN)("The 'cms' setting for 'oplmode' is deprecated; use 'cms = on' instead.");
+            sb.cms = true;
+        }
+        else {
+            const auto cms_str = section->Get_string("cms");
+            if(cms_str == "on") {
+                sb.cms = true;
+            }
+            else if(cms_str == "auto") {
+                sb.cms = (sb.type == SBT_1 || sb.type == SBT_GB);
+            }
+            else
+                sb.cms = false;
+        }
+
+        switch(sb.type) {
+        case SBT_1: // CMS is optional for Sound Blaster 1 and 2
+        case SBT_2:;
+        case SBT_GB:
+            if(!sb.cms) {
+                LOG(LOG_SB, LOG_WARN)("'cms' setting is 'off', but is forced to 'auto' on the Game Blaster.");
+                auto* sect_updater = static_cast<Section_prop*>(control->GetSection("sblaster"));
+                sect_updater->Get_prop("cms")->SetValue("auto");
+            }
+            sb.cms = true; // Game Blaster is CMS
+        default:
+            if(sb.cms) {
+                LOG(LOG_SB, LOG_WARN)("'cms' setting 'on' not supported on this card, forcing 'auto'.");
+                auto* sect_updater = static_cast<Section_prop*>(control->GetSection("sblaster"));
+                sect_updater->Get_prop("cms")->SetValue("auto");
+            }
+            sb.cms = false;
+        }
+
+        if(sb.cms) {
+            CMS_Init(section);
+        }
+
         if (sb.type==SBT_NONE || sb.type==SBT_GB) return;
 
         sb.chan=MixerChan.Install(&SBLASTER_CallBack,22050,"SB");
@@ -4227,12 +4259,7 @@ ASP>
         switch (oplmode) {
         case OPL_none:
             break;
-        case OPL_cms:
-            CMS_ShutDown(m_configuration);
-            break;
         case OPL_opl2:
-            CMS_ShutDown(m_configuration);
-            // fall-through
         case OPL_dualopl2:
         case OPL_opl3:
         case OPL_opl3gold:
@@ -4242,6 +4269,9 @@ ASP>
         default:
             break;
         }
+        if(sb.cms) {
+            CMS_ShutDown(m_configuration);
+        }
         if (sb.type==SBT_NONE || sb.type==SBT_GB) return;
         DSP_Reset(); // Stop everything
     }