Merge pull request #741 from edge-classic/fp-mixer

Migrate to floating point audio mixing; simplify blitting and mono vs. stereo audio processing

Author: dashodanger

docs/licenses/License Attribution.txt

@@ -25,9 +25,6 @@ libRAD (patches.cpp/radmidi.cpp) - Copyright (c) 2021-2023 Devin Acker
 Mod4Play library - 	Copyright (c) 2024 dashodanger
 					Copyright (c) 2022 Olav Sørensen
 
-minivorbis library - Copyright (c) 2020 Eduardo Bart
-		     		 Copyright (c) 2002-2020 Xiph.org Foundation
-
 ZDoom FName implementation - Copyright (c) 2005-2007 Randy Heit
 
 ===========================================================================================
@@ -139,7 +136,7 @@ prns.h - Marc B. Reynolds
 
 "sf_GMbank" soundfont (renamed to Default.sf2) - The Csound Developers
 
-stb_image, stb_image_write, stb_rect_pack, stb_sprintf and stb_truetype libraries - Sean Barrett
+stb_image, stb_image_write, stb_rect_pack, stb_sprintf, stb_truetype and stb_vorbis libraries - Sean Barrett
 
 ===========================================================================================
 SIL Open Font License

libraries/CMakeLists.txt

@@ -1,7 +1,6 @@
 add_subdirectory(almostequals)
 add_subdirectory(crsid)
 add_subdirectory(dr_libs)
-add_subdirectory(fmmidi)
 add_subdirectory(fluidlite)
 if (NOT EDGE_GL_ES2)
   add_subdirectory(glad)
@@ -13,7 +12,6 @@ add_subdirectory(libRAD)
 add_subdirectory(libvwad)
 add_subdirectory(lua)
 add_subdirectory(m4p)
-add_subdirectory(minivorbis)
 add_subdirectory(miniz)
 add_subdirectory(pl_mpeg)
 add_subdirectory(prns)

libraries/crsid/host/audio.c

@@ -1,3 +1,5 @@
+#include <stdint.h>
+
 void cRSID_generateSound(cRSID_C64instance *C64, unsigned char *buf, unsigned short len)
 {
     static unsigned short i;
@@ -18,6 +20,29 @@ void cRSID_generateSound(cRSID_C64instance *C64, unsigned char *buf, unsigned sh
     }
 }
 
+void cRSID_generateFloat(cRSID_C64instance *C64, float *buf, unsigned short len)
+{
+    static unsigned short i;
+    static unsigned char  j;
+    static cRSID_Output   Output;
+    static int16_t   OutputL, OutputR;
+
+    for (i = 0; i < len; i += 8)
+    {
+        for (j = 0; j < C64->PlaybackSpeed; ++j)
+            Output = cRSID_generateSample(C64);
+#if defined _MSC_VER || (defined __SIZEOF_FLOAT__ && __SIZEOF_FLOAT__ == 4)
+        *(uint32_t *)buf=0x43818000^((uint16_t)Output.L * C64->MainVolume / 256);
+        *buf++ -= 259.0f;
+        *(uint32_t *)buf=0x43818000^((uint16_t)Output.R * C64->MainVolume / 256);
+        *buf++ -= 259.0f;
+#else   
+        *buf++ = (float)(Output.L * C64->MainVolume / 256) * 0.000030517578125f;
+        *buf++ = (float)(Output.R * C64->MainVolume / 256) * 0.000030517578125f;
+#endif
+    }
+}
+
 static inline cRSID_Output cRSID_generateSample(cRSID_C64instance *C64)
 { // call this from custom buffer-filler
     static cRSID_Output Output;

libraries/crsid/libcRSID.h

@@ -102,6 +102,7 @@ extern "C"
 
     // host/audio.c
     void cRSID_generateSound(cRSID_C64instance *C64, unsigned char *buf, unsigned short len);
+    void cRSID_generateFloat(cRSID_C64instance *C64, float *buf, unsigned short len);
 
     struct cRSID_SIDheader
     {                             // Offset:   default/info: