From b3a7f8f1fceddcd45ec62bcbf75ba128e4f84f5a Mon Sep 17 00:00:00 2001
From: Nebuleon Fumika
Date: Sun, 3 Feb 2013 19:26:34 -0500
Subject: Synchronise the controller status more spread out inside a rendered
 frame: * before rendering a background; * before rendering sprites; * while
 rendering more than 128 samples of audio at once ("Prefer fluid video"); *
 after every 16 scanlines of CPU execution instead of every 1; * while waiting
 for an audio buffer to become available; * while killing time between frames
 with fast-forward disabled.

Controller presses and releases are now combined in a DS button bitfield using a shorter 32-bit algorithm. See entry.cpp:NDSSFCAccumulateJoypad and #define ACCUMULATE_JOYPAD in the source.

This is still not suitable for playing platformers frame-perfectly, but it's much better than half a second of latency to press or release a button, and one still needs to press buttons a bit more than just light taps. I'd say 50 milliseconds is the latency now. Platformers requiring more precision can be played with frameskip 0.

DMA does not require double-buffered displaying, so synchronise the controller more often by disabling double-buffered displaying again.
---
 source/soundux.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'source/soundux.cpp')

diff --git a/source/soundux.cpp b/source/soundux.cpp
index dde8a14..c20f366 100644
--- a/source/soundux.cpp
+++ b/source/soundux.cpp
@@ -1233,6 +1233,15 @@ static inline void MixMono (int sample_count)
 		
 		for (uint32 I = 0; I < (uint32) sample_count; I++)
 		{
+#ifdef ACCUMULATE_JOYPAD
+/*
+ * This call allows NDSSFC to synchronise the DS controller more often.
+ * If porting a later version of Snes9x into NDSSFC, it is essential to
+ * preserve it.
+ */
+			if ((I & 0x7F) == 0x7F)
+				NDSSFCAccumulateJoypad ();
+#endif
 			unsigned long freq = freq0;
 			
 			if (mod)
-- 
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