Merge pull request #53 from Dwedit/submission_1

Add support for Audio/Video Disable flags and Hard Disable Audio

6 files changed, 76 insertions, 3 deletions

diff --git a/libretro.c b/libretro.c
index 47729b0..8625c57 100644
--- a/libretro.c
+++ b/libretro.c
@@ -428,6 +428,8 @@ static int32_t samples_to_play = 0;
 void retro_run(void)
 {
    bool updated = false;
+   int result;
+   bool okay;
 #ifndef USE_BLARGG_APU
    static int16_t audio_buf[2048];
 #endif
@@ -440,6 +442,24 @@ void retro_run(void)
    IPPU.RenderThisFrame = false;
 #endif
 
+   result = -1;
+   okay = environ_cb(RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE, &result);
+   if (okay)
+   {
+      bool audioEnabled = 0 != (result & 2);
+      bool videoEnabled = 0 != (result & 1);
+      bool hardDisableAudio = 0 != (result & 8);
+      IPPU.RenderThisFrame = videoEnabled;
+      S9xSetSoundMute(!audioEnabled || hardDisableAudio);
+      Settings.HardDisableAudio = hardDisableAudio;
+   }
+   else
+   {
+      IPPU.RenderThisFrame = true;
+      S9xSetSoundMute(false);
+      Settings.HardDisableAudio = false;
+   }
+
    poll_cb();
 
    RETRO_PERFORMANCE_INIT(S9xMainLoop_func);
diff --git a/libretro.h b/libretro.h
index 469b86a..ed1902b 100644
--- a/libretro.h
+++ b/libretro.h
@@ -901,6 +901,47 @@ enum retro_mod
                                             * writeable (and readable).
                                             */
 
+#define RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE (47 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* int * --
+                                            * Tells the core if the frontend wants audio or video.
+                                            * If disabled, the frontend will discard the audio or video,
+                                            * so the core may decide to skip generating a frame or generating audio.
+                                            * This is mainly used for increasing performance.
+                                            * Bit 0 (value 1): Enable Video
+                                            * Bit 1 (value 2): Enable Audio
+                                            * Bit 2 (value 4): Use Fast Savestates.
+                                            * Bit 3 (value 8): Hard Disable Audio
+                                            * Other bits are reserved for future use and will default to zero.
+                                            * If video is disabled:
+                                            * * The frontend wants the core to not generate any video,
+                                            *   including presenting frames via hardware acceleration.
+                                            * * The frontend's video frame callback will do nothing.
+                                            * * After running the frame, the video output of the next frame should be
+                                            *   no different than if video was enabled, and saving and loading state
+                                            *   should have no issues.
+                                            * If audio is disabled:
+                                            * * The frontend wants the core to not generate any audio.
+                                            * * The frontend's audio callbacks will do nothing.
+                                            * * After running the frame, the audio output of the next frame should be
+                                            *   no different than if audio was enabled, and saving and loading state
+                                            *   should have no issues.
+                                            * Fast Savestates:
+                                            * * Guaranteed to be created by the same binary that will load them.
+                                            * * Will not be written to or read from the disk.
+                                            * * Suggest that the core assumes loading state will succeed.
+                                            * * Suggest that the core updates its memory buffers in-place if possible.
+                                            * * Suggest that the core skips clearing memory.
+                                            * * Suggest that the core skips resetting the system.
+                                            * * Suggest that the core may skip validation steps.
+                                            * Hard Disable Audio:
+                                            * * Used for a secondary core when running ahead.
+                                            * * Indicates that the frontend will never need audio from the core.
+                                            * * Suggests that the core may stop synthesizing audio, but this should not
+                                            *   compromise emulation accuracy.
+                                            * * Audio output for the next frame does not matter, and the frontend will
+                                            *   never need an accurate audio state in the future.
+                                            * * State will never be saved when using Hard Disable Audio.
+                                            */
 enum retro_hw_render_interface_type
 {
    RETRO_HW_RENDER_INTERFACE_VULKAN = 0,
diff --git a/source/apu_blargg.c b/source/apu_blargg.c
index 49f5491..2976580 100644
--- a/source/apu_blargg.c
+++ b/source/apu_blargg.c
@@ -761,7 +761,8 @@ V(V9_V6_V3,2) -> V(V9,2) V(V6,3) V(V3,4) */
 static void dsp_run( int32_t clocks_remain )
 {
    int32_t phase;
-
+   if (Settings.HardDisableAudio)
+	   return;
    phase = dsp_m.phase;
    dsp_m.phase = (phase + clocks_remain) & 31;
 
@@ -3259,6 +3260,11 @@ static int8_t const reg_times_ [256] =
    29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
 };
 
+void S9xSetSoundMute(bool mute)
+{
+	Settings.Mute = mute;
+}
+
 bool S9xInitAPU()
 {
    int32_t i;
diff --git a/source/gfx.c b/source/gfx.c
index 1b9928d..a43ef35 100644
--- a/source/gfx.c
+++ b/source/gfx.c
@@ -478,10 +478,10 @@ void S9xEndScreenRefresh(void)
 
       GFX.Pitch = GFX.Pitch2 = GFX.RealPitch;
       GFX.PPL = GFX.PPLx2 >> 1;
+   }
 #ifdef LAGFIX
-      finishedFrame = true;
+   finishedFrame = true;
 #endif
-   }
 
    S9xApplyCheats();
 
diff --git a/source/memmap.c b/source/memmap.c
index d5c29b1..4f76fc8 100644
--- a/source/memmap.c
+++ b/source/memmap.c
@@ -24,6 +24,11 @@
 #include <malloc.h>
 #endif
 
+#ifdef _MSC_VER
+/* Necessary to build on MSVC */
+#define strnicmp _strnicmp
+#endif
+
 #define MAP_HIROM_SRAM_OR_NONE (Memory.SRAMSize == 0 ? (uint8_t*) MAP_NONE : (uint8_t*) MAP_HIROM_SRAM)
 #define MAP_LOROM_SRAM_OR_NONE (Memory.SRAMSize == 0 ? (uint8_t*) MAP_NONE : (uint8_t*) MAP_LOROM_SRAM)
 #define MAP_RONLY_SRAM_OR_NONE (Memory.SRAMSize == 0 ? (uint8_t*) MAP_NONE : (uint8_t*) MAP_RONLY_SRAM)
diff --git a/source/snes9x.h b/source/snes9x.h
index 11dc1ff..ad410e1 100644
--- a/source/snes9x.h
+++ b/source/snes9x.h
@@ -214,6 +214,7 @@ typedef struct
    bool     Justifier;
    bool     SecondJustifier;
    int8_t   SETA;
+   bool     HardDisableAudio;
 } SSettings;
 
 extern SSettings Settings;