qsoundhle: Saturate ROM offsets [superctr]

qsound: Apply ADPCM sample bank [superctr]

src/devices/sound/qsound.cpp

@@ -283,7 +283,7 @@ READ16_MEMBER(qsound_device::dsp_sample_r)
 	// FIXME: DSP16 doesn't like bytes, only signed words - should this zero-pad or byte-smear?
 	u8 const byte(read_byte((u32(m_rom_bank) << 16) | m_rom_offset));
 	if (!machine().side_effects_disabled())
-		m_rom_bank = offset;
+		m_rom_bank = (m_rom_bank & 0x8000U) | offset;
 	return (u16(byte) << 8) | u16(byte);
 }
 
@@ -331,24 +331,10 @@ WRITE_LINE_MEMBER(qsound_device::dsp_ock_w)
 
 WRITE16_MEMBER(qsound_device::dsp_pio_w)
 {
-	/*
+	// PDX0 is used for QSound ROM offset, and PDX1 is used for ADPCM ROM offset
-	 *  FIXME: what does this do when PDX is high?
+	// this prevents spurious PSEL transitions between sending samples to the DAC
-	 *  There are seemingly two significant points where the program writes PDX1 every sample interval.
+	// it could still be used to have separate QSound/ADPCM ROM banks
-	 *
+	m_rom_bank = (m_rom_bank & 0x7fffU) | u16(offset << 15);
-	 *  Before writing the right-channel sample to SDX - this causes the PSEL 0->1 transition:
-	 *  0:5d4: 996e       if true a0 = rnd(a0)
-	 *  0:5d5: 51e0 0000  pdx1 = 0x0000
-	 *  0:5d7: 49a0       move sdx = a0
-	 *
-	 * This curious code where it writes out the a word from RAM@0x00f1 - this value seems significant:
-	 * 0:335: 18f1       set r0 = 0x00f1
-	 * 0:336: 3cd0       nop, a0 = *r0
-	 * 0:337: d850       p = x*y, y = a1, x = *pt++i
-	 * 0:338: 49e0       move pdx1 = a0
-	 */
-	if (offset)
-		LOG("QSound: DSP PDX1 = %04X\n", data);
-	else
 	m_rom_offset = data;
 }
 

src/devices/sound/qsoundhle.cpp

@@ -29,6 +29,19 @@
 #include "emu.h"
 #include "qsoundhle.h"
 
+#include <algorithm>
+#include <limits>
+
+
+namespace {
+
+constexpr u32 saturate(s64 val)
+{
+	return std::min<s64>(std::max<s64>(val, std::numeric_limits<s32>::min()), std::numeric_limits<s32>::max());
+}
+
+} // anonymous namespace
+
 // device type definition
 DEFINE_DEVICE_TYPE(QSOUND_HLE, qsound_hle_device, "qsound_hle", "QSound (HLE)")
 
@@ -41,7 +54,7 @@ DEFINE_DEVICE_TYPE(QSOUND_HLE, qsound_hle_device, "qsound_hle", "QSound (HLE)")
 //  qsound_hle_device - constructor
 //-------------------------------------------------
 
-qsound_hle_device::qsound_hle_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+qsound_hle_device::qsound_hle_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
 	: device_t(mconfig, QSOUND_HLE, tag, owner, clock)
 	, device_sound_interface(mconfig, *this)
 	, device_rom_interface(mconfig, *this, 24)
@@ -124,14 +137,14 @@ void qsound_hle_device::sound_stream_update(sound_stream &stream, stream_sample_
 			offs_t const addr(ch.reg[1] | (bank << 16));
 
 			// update based on playback rate
-			uint32_t updated(uint32_t(ch.reg[2] << 4) + ((uint32_t(ch.reg[1]) << 16) | ch.reg[3]));
+			s64 updated(s32(u32(ch.reg[2]) << 4) + s32((u32(ch.reg[1]) << 16) | ch.reg[3]));
-			ch.reg[3] = uint16_t(updated);
+			ch.reg[3] = u16(saturate(updated));
-			if (updated >= (uint32_t(ch.reg[5]) << 16))
+			if (updated >= s32(u32(ch.reg[5]) << 16))
-				updated -= uint32_t(ch.reg[4]) << 16;
+				updated -= s32(u32(ch.reg[4]) << 16);
-			ch.reg[1] = uint16_t(updated >> 16);
+			ch.reg[1] = u16(saturate(updated) >> 16);
 
 			// get the scaled sample
-			int32_t const scaled(int32_t(int16_t(ch.reg[6])) * read_sample(addr));
+			s32 const scaled(s32(s16(ch.reg[6])) * read_sample(addr));
 
 			// apply simple panning
 			*lmix++ += (((scaled >> 8) * ch.lvol) >> 14);
@@ -172,7 +185,7 @@ READ8_MEMBER(qsound_hle_device::qsound_r)
 }
 
 
-void qsound_hle_device::write_data(uint8_t address, uint16_t data)
+void qsound_hle_device::write_data(u8 address, u16 data)
 {
 	int ch = 0, reg;
 

src/devices/sound/qsoundhle.h

@@ -34,13 +34,12 @@ protected:
 	virtual void rom_bank_updated() override;
 
 private:
-
 	// MAME resources
 	sound_stream *m_stream;
 
 	struct qsound_channel
 	{
-		uint16_t reg[8];    // channel control registers
+		u16 reg[8];    // channel control registers
 
 		// work variables
 		int lvol;           // left volume
@@ -48,10 +47,10 @@ private:
 	} m_channel[16];
 
 	int m_pan_table[33];    // pan volume table
-	uint16_t m_data;        // register latch data
+	u16 m_data;        // register latch data
 
-	inline int16_t read_sample(uint32_t offset) { return uint16_t(read_byte(offset)) << 8; }
+	inline s16 read_sample(u32 offset) { return u16(read_byte(offset)) << 8; }
-	void write_data(uint8_t address, uint16_t data);
+	void write_data(u8 address, u16 data);
 };
 
 DECLARE_DEVICE_TYPE(QSOUND_HLE, qsound_hle_device)