wavemotion-dave/GimliDS
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Version 0.7 with more SID filter improvements.

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This commit is contained in:
Dave Bernazzani 2025-04-26 09:17:13 -04:00
parent 36c78b296d
commit 35553538d0
5 changed files with 21 additions and 18 deletions
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2
Makefile
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@ -9,7 +9,7 @@ include $(DEVKITARM)/ds_rules
export TARGET := GimliDS export TARGET := GimliDS
export TOPDIR := $(CURDIR) export TOPDIR := $(CURDIR)
export VERSION := 0.6 export VERSION := 0.7
ICON := -b $(CURDIR)/C64_icon.bmp "GimliDS $(VERSION);wavemotion-dave;https://github.com/wavemotion-dave/GimliDS" ICON := -b $(CURDIR)/C64_icon.bmp "GimliDS $(VERSION);wavemotion-dave;https://github.com/wavemotion-dave/GimliDS"

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arm9/gfx_data/intro.png
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2
arm9/source/C64.cpp
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@ -860,7 +860,7 @@ ITCM_CODE void C64::VBlank(bool draw_frame)
{ {
if (ThePrefs.TrueDrive && TheDisplay->led_state[0]) break; // If reading the drive in 'true drive' mode, just plow along... if (ThePrefs.TrueDrive && TheDisplay->led_state[0]) break; // If reading the drive in 'true drive' mode, just plow along...
asm("nop"); asm("nop");
break; // Uncomment this for full speed... //break; // Uncomment this for full speed...
} }
frames_per_sec++; frames_per_sec++;

2
arm9/source/Display.cpp
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@ -447,7 +447,7 @@ int i = 0;
int debug[8]={0,0,0,0,0,0,0,0}; int debug[8]={0,0,0,0,0,0,0,0};
void C64Display::Speedometer(int speed) void C64Display::Speedometer(int speed)
{ {
#if 1 #if 0
char tmp[34]; char tmp[34];
sprintf(tmp, "%-8d", speed); sprintf(tmp, "%-8d", speed);

33
arm9/source/SID.cpp
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@ -75,10 +75,8 @@ uint32_t sid_random_seed __attribute__((section(".dtcm"))); // Random seed
*/ */
#define CALC_RESONANCE_LP(f) (227.755 - 1.7635 * f - 0.0176385 * f * f + 0.00333484 * f * f * f) #define CALC_RESONANCE_LP(f) (227.755 - 1.7635 * f - 0.0176385 * f * f + 0.00333484 * f * f * f)
#define CALC_RESONANCE_HP(f) (366.374 - 14.0052 * f + 0.603212 * f * f - 0.000880196 * f * f * f) #define CALC_RESONANCE_HP(f) (366.374 - 14.0052 * f + 0.603212 * f * f - 0.000880196 * f * f * f)
/* /*
* Random number generator for noise waveform * Random number generator for noise waveform
*/ */
@ -362,6 +360,7 @@ private:
uint8 f_type; // Filter type uint8 f_type; // Filter type
uint8 f_freq; // SID filter frequency (upper 8 bits) uint8 f_freq; // SID filter frequency (upper 8 bits)
uint8 f_freq_low; // SID filter frequency (lower 4 bits)
uint8 f_res; // Filter resonance (0..15) uint8 f_res; // Filter resonance (0..15)
#ifdef USE_FIXPOINT_MATHS #ifdef USE_FIXPOINT_MATHS
FixPoint f_ampl; FixPoint f_ampl;
@ -369,16 +368,16 @@ private:
int32 xn1, xn2, yn1, yn2; // can become very large int32 xn1, xn2, yn1, yn2; // can become very large
FixPoint sidquot; FixPoint sidquot;
#ifdef PRECOMPUTE_RESONANCE #ifdef PRECOMPUTE_RESONANCE
FixPoint resonanceLP[256]; FixPoint resonanceLP[257];
FixPoint resonanceHP[256]; FixPoint resonanceHP[257];
#endif #endif
#else #else
float f_ampl; // IIR filter input attenuation float f_ampl; // IIR filter input attenuation
float d1, d2, g1, g2; // IIR filter coefficients float d1, d2, g1, g2; // IIR filter coefficients
float xn1, xn2, yn1, yn2; // IIR filter previous input/output signal float xn1, xn2, yn1, yn2; // IIR filter previous input/output signal
#ifdef PRECOMPUTE_RESONANCE #ifdef PRECOMPUTE_RESONANCE
float resonanceLP[256]; // shortcut for calc_filter float resonanceLP[257]; // shortcut for calc_filter
float resonanceHP[256]; float resonanceHP[257];
#endif #endif
#endif #endif
int16 *sound_buffer; int16 *sound_buffer;
@ -733,7 +732,7 @@ DigitalRenderer::DigitalRenderer()
#ifdef PRECOMPUTE_RESONANCE #ifdef PRECOMPUTE_RESONANCE
#ifdef USE_FIXPOINT_MATHS #ifdef USE_FIXPOINT_MATHS
// slow floating point doesn't matter much on startup! // slow floating point doesn't matter much on startup!
for (int i=0; i<256; i++) { for (int i=0; i<257; i++) {
resonanceLP[i] = FixNo(CALC_RESONANCE_LP(i)); resonanceLP[i] = FixNo(CALC_RESONANCE_LP(i));
resonanceHP[i] = FixNo(CALC_RESONANCE_HP(i)); resonanceHP[i] = FixNo(CALC_RESONANCE_HP(i));
} }
@ -742,7 +741,7 @@ DigitalRenderer::DigitalRenderer()
// compute lookup table for sin and cos // compute lookup table for sin and cos
InitFixSinTab(); InitFixSinTab();
#else #else
for (int i=0; i<256; i++) { for (int i=0; i<257; i++) {
resonanceLP[i] = CALC_RESONANCE_LP(i); resonanceLP[i] = CALC_RESONANCE_LP(i);
resonanceHP[i] = CALC_RESONANCE_HP(i); resonanceHP[i] = CALC_RESONANCE_HP(i);
} }
@ -778,6 +777,7 @@ void DigitalRenderer::Reset(void)
f_type = FILT_NONE; f_type = FILT_NONE;
f_freq = f_res = 0; f_freq = f_res = 0;
f_freq_low = 0;
#ifdef USE_FIXPOINT_MATHS #ifdef USE_FIXPOINT_MATHS
f_ampl = FixNo(1); f_ampl = FixNo(1);
d1 = d2 = g1 = g2 = 0; d1 = d2 = g1 = g2 = 0;
@ -873,11 +873,14 @@ void DigitalRenderer::WriteRegister(uint16 adr, uint8 byte)
voice[v].r_sub = EGTable[byte & 0xf]; voice[v].r_sub = EGTable[byte & 0xf];
break; break;
case 22: case 21: // Filter Frequency - lower 3 bits
if (byte != f_freq) { f_freq_low = ((byte & 0x7) > 3) ? 1:0;
f_freq = byte; calc_filter();
calc_filter(); break;
}
case 22: // Filter Frequency - upper 8 bits
f_freq = byte;
calc_filter();
break; break;
case 23: case 23:
@ -954,13 +957,13 @@ void DigitalRenderer::calc_filter(void)
// Calculate resonance frequency // Calculate resonance frequency
if (f_type == FILT_LP || f_type == FILT_LPBP) if (f_type == FILT_LP || f_type == FILT_LPBP)
#ifdef PRECOMPUTE_RESONANCE #ifdef PRECOMPUTE_RESONANCE
fr = resonanceLP[f_freq]; fr = resonanceLP[f_freq + f_freq_low];
#else #else
fr = CALC_RESONANCE_LP(f_freq); fr = CALC_RESONANCE_LP(f_freq);
#endif #endif
else else
#ifdef PRECOMPUTE_RESONANCE #ifdef PRECOMPUTE_RESONANCE
fr = resonanceHP[f_freq]; fr = resonanceHP[f_freq+f_freq_low];
#else #else
fr = CALC_RESONANCE_HP(f_freq); fr = CALC_RESONANCE_HP(f_freq);
#endif #endif