Echo 1.6 release... kind of a mess, will clean up in further commits I guess

1 files changed, 23 insertions, 1 deletions

diff --git a/doc/api-asm.68k b/doc/api-asm.68k
index 3293b9e..8cbbdba 100644
--- a/doc/api-asm.68k
+++ b/doc/api-asm.68k
@@ -132,7 +132,9 @@ Echo_SetVolumeEx
    Sets the global volume for each channel separately. Register a0 points to
    a list of 16 bytes (one for each Echo channel). Values for FM and PSG
    channels are given in the same way as in events, that is: logarithmic
-   scale, 0..127 for FM, 0..15 for PSG, lower = louder.
+   scale, 0..127 for FM, 0..15 for PSG, lower = louder. You can use the
+   look-up tables described below (Echo_FMVolTable and Echo_PSGVolTable) to
+   convert from linear to .
    
    The last byte (the one belonging to the PCM channel) is used to toggle
    whether PCM plays, either 0 (disabled) or 1 (enabled).
@@ -141,6 +143,17 @@ Echo_SetVolumeEx
    been changed for the sake of expansion. Currently the extra bytes are
    ignored, but consider adapting your code (just set them to zero).
 
+Echo_FMVolTable
+Echo_PSGVolTable
+    These two are not subroutines but rather look-up tables. They have 64
+    byte-sized entries and they're used to convert a linear volume value into
+    a hardware volume value (e.g. for Echo_SetVolumeEx).
+    
+    To give an idea of how to use these: take what you'd pass in d0 to
+    Echo_SetVolume divided by 4 (shift right by 2), then use it as an offset
+    to these tables. The byte will be the volume as the hardware (or
+    Echo_SetVolumeEx) wants it.
+
 =============================================================================
 
 *** Settings ***
@@ -167,6 +180,15 @@ Echo_SetPCMRate
    (which can hamper Echo's ability to process complex streams). Be careful
    if you increase the sample rate.
 
+Echo_SetStereo
+   in d0 = $00 to use mono, otherwise to use stereo
+   
+   Toggles whether sound is forced to mono (d0 == $00) or if stereo panning
+   works (d0 != $00). Will take effect for all following panning events. Can
+   be used to implement a mono/stereo toggle in games.
+   
+   By default Echo is in stereo mode.
+
 =============================================================================
 
 *** Raw access ***