make samplerate adjustable

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>

examples/Makefile

@@ -42,7 +42,7 @@ OBJS = \
 	libgbfs.o \
 	gbfs_stdio.o
 
-MODULES = $(shell find data -iname *.xm)
+MODULES = $(shell find data -iname *.xm -or -iname *.mod)
 
 BIN_MODULES = $(MODULES:=.bin)
 

src/pimp_config.h

@@ -11,7 +11,7 @@
 
 /* check the sample-rate calculator at http://www.pineight.com/gba/samplerates/ for more glitch-free samplerates */
 /* 0x4000100 = 0xFFFF, 0x4000102 = 0x0083 */
-#define PIMP_SAMPLERATE (18157.16)
+#define PIMP_GBA_SAMPLERATE (18157.16)
 /* #define PIMP_SAMPLERATE (31536.12) */
 
 /* enable / disable assert */

src/pimp_gba.c

@@ -61,7 +61,7 @@ static struct pimp_mod_context pimp_gba_ctx   EWRAM_DATA;
 
 /* setup some constants */
 #define CYCLES_PR_FRAME 280896
-#define CYCLES_PR_SAMPLE  ((int)((1 << 24) / ((float)PIMP_SAMPLERATE)))
+#define CYCLES_PR_SAMPLE  ((int)((1 << 24) / ((float)PIMP_GBA_SAMPLERATE)))
 #define SOUND_BUFFER_SIZE ((int)((float)CYCLES_PR_FRAME / CYCLES_PR_SAMPLE))
 
 /* mix and playback-buffers */
@@ -73,7 +73,7 @@ void pimp_gba_init(const struct pimp_module *module, const void *sample_bank)
 {
 	u32 zero = 0;
 	pimp_gba_mixer.mix_buffer = pimp_gba_mix_buffer;
-	pimp_mod_context_init(&pimp_gba_ctx, (const pimp_module*)module, (const u8*)sample_bank, &pimp_gba_mixer);
+	pimp_mod_context_init(&pimp_gba_ctx, (const pimp_module*)module, (const u8*)sample_bank, &pimp_gba_mixer, PIMP_GBA_SAMPLERATE);
 	
 	CpuFastSet(&zero, &pimp_gba_sound_buffers[0][0], DMA_SRC_FIXED | ((SOUND_BUFFER_SIZE / 4) * 2));
 	REG_SOUNDCNT_H = SNDA_VOL_100 | SNDA_L_ENABLE | SNDA_R_ENABLE | SNDA_RESET_FIFO;

src/pimp_math.c

@@ -44,17 +44,15 @@ unsigned pimp_get_linear_period(int note, int fine_tune)
 }
 
 #include "linear_delta_lut.h"
-unsigned pimp_get_linear_delta(unsigned period)
+unsigned pimp_get_linear_delta(unsigned int period, unsigned int delta_scale)
 {
-	const unsigned int scale = (unsigned int)((1.0 / (PIMP_SAMPLERATE)) * (1 << 3) * (1ULL << 32));
-	
 	unsigned p = (12 * 16 * 4 * 14) - period;
 	unsigned octave        = p / (12 * 16 * 4);
 	unsigned octave_period = p % (12 * 16 * 4);
 	unsigned delta = linear_delta_lut[octave_period] << octave;
 	
 	/* BEHOLD: the expression of the devil (this compiles to one arm-instruction) */
-	delta = ((long long)delta * scale + (1ULL << 31)) >> 32;
+	delta = ((long long)delta * (delta_scale >> 3) + (1ULL << 31)) >> 32;
 	return delta;
 }
 #endif /* NO_LINEAR_PERIODS */
@@ -92,10 +90,8 @@ unsigned pimp_get_amiga_period(int note, int fine_tune)
 #include "amiga_delta_lut.h"
 #define AMIGA_DELTA_LUT_SIZE (1 << AMIGA_DELTA_LUT_LOG2_SIZE)
 #define AMIGA_DELTA_LUT_FRAC_BITS (15 - AMIGA_DELTA_LUT_LOG2_SIZE)
-unsigned pimp_get_amiga_delta(unsigned period)
+unsigned pimp_get_amiga_delta(unsigned int period, unsigned int delta_scale)
 {
-	const unsigned int scale = (unsigned int)(((1.0 / (PIMP_SAMPLERATE)) * (1 << 6)) * (1LL << 32));
-	
 	int d1, d2;
 	unsigned int delta;
 	unsigned int shamt = clz16(period) - 1;
@@ -112,7 +108,7 @@ unsigned pimp_get_amiga_delta(unsigned period)
 	else delta >>= AMIGA_DELTA_LUT_FRAC_BITS - shamt;
 	
 	/* BEHOLD: the expression of the devil 2.0 (this compiles to one arm-instruction) */
-	delta = ((long long)delta * scale + (1ULL << 31)) >> 32;
+	delta = ((long long)delta * delta_scale + (1ULL << 31)) >> 32;
 	return delta;
 }
 #endif /* NO_AMIGA_PERIODS */

src/pimp_math.h

@@ -48,12 +48,12 @@ static INLINE unsigned clz8(unsigned input)
 
 
 #ifndef NO_LINEAR_PERIODS
-unsigned pimp_get_linear_delta(unsigned period);
+unsigned pimp_get_linear_delta(unsigned int period, unsigned int delta_scale);
 unsigned pimp_get_linear_period(int note, int fine_tune);
 #endif
 
 #ifndef NO_AMIGA_PERIODS
-unsigned pimp_get_amiga_delta(unsigned period);
+unsigned pimp_get_amiga_delta(unsigned period, unsigned int delta_scale);
 unsigned pimp_get_amiga_period(int note, int fine_tune);
 #endif
 

src/pimp_mod_context.c

@@ -5,7 +5,7 @@
 
 #include "pimp_mod_context.h"
 
-void pimp_mod_context_init(struct pimp_mod_context *ctx, const pimp_module *mod, const u8 *sample_bank, struct pimp_mixer *mixer)
+void pimp_mod_context_init(struct pimp_mod_context *ctx, const pimp_module *mod, const u8 *sample_bank, struct pimp_mixer *mixer, const float samplerate)
 {
 	int i;
 	ASSERT(ctx != NULL);
@@ -13,6 +13,7 @@ void pimp_mod_context_init(struct pimp_mod_context *ctx, const pimp_module *mod,
 	ctx->mod = mod;
 	ctx->sample_bank = sample_bank;
 	ctx->mixer = mixer;
+	pimp_mod_context_set_samplerate(ctx, samplerate);
 	
 	/* setup default player-state */
 	ctx->tick_len      = 0;
@@ -69,6 +70,12 @@ void pimp_mod_context_init(struct pimp_mod_context *ctx, const pimp_module *mod,
 	pimp_mixer_reset(ctx->mixer);
 }
 
+void pimp_mod_context_set_samplerate(struct pimp_mod_context *ctx, const float samplerate)
+{
+	ctx->samplerate = samplerate;
+	ctx->delta_scale = (unsigned int)((1.0 / samplerate) * (1 << 6) * (1ULL << 32));
+}
+
 /* "hard" jump in a module */
 void pimp_mod_context_set_pos(struct pimp_mod_context *ctx, int row, int order)
 {
@@ -142,7 +149,7 @@ void pimp_mod_context_set_next_pos(struct pimp_mod_context *ctx, int row, int or
 void pimp_mod_context_set_bpm(struct pimp_mod_context *ctx, int bpm)
 {
 	/* we're using 8 fractional-bits for the tick-length */
-	const int temp = (int)(((PIMP_SAMPLERATE) * 5) * (1 << 8));
+	const int temp = (int)((ctx->samplerate * 5) * (1 << 8));
 	
 	ASSERT(ctx != NULL);
 	ASSERT(bpm > 0);

src/pimp_mod_context.h

@@ -44,10 +44,15 @@ struct pimp_mod_context
 	const pimp_module *mod;
 	struct pimp_mixer *mixer;
 	
+	float samplerate;
+	unsigned int delta_scale;
+	
 	pimp_callback callback;
 };
 
-void pimp_mod_context_init(struct pimp_mod_context *ctx, const pimp_module *mod, const u8 *sample_bank, struct pimp_mixer *mixer);
+void pimp_mod_context_init(struct pimp_mod_context *ctx, const pimp_module *mod, const u8 *sample_bank, struct pimp_mixer *mixer, const float samplerate);
+void pimp_mod_context_set_samplerate(struct pimp_mod_context *ctx, const float samplerate);
+
 void pimp_mod_context_set_bpm(struct pimp_mod_context *ctx, int bpm);
 void pimp_mod_context_set_tempo(struct pimp_mod_context *ctx, int tempo);
 

src/pimp_render.c

@@ -454,11 +454,11 @@ static void pimp_mod_context_update_row(struct pimp_mod_context *ctx)
 		{
 			if (ctx->mod->flags & FLAG_LINEAR_PERIODS)
 			{
-				mc->sample_cursor_delta = pimp_get_linear_delta(chan->final_period);
+				mc->sample_cursor_delta = pimp_get_linear_delta(chan->final_period, ctx->delta_scale);
 			}
 			else
 			{
-				mc->sample_cursor_delta = pimp_get_amiga_delta(chan->final_period);
+				mc->sample_cursor_delta = pimp_get_amiga_delta(chan->final_period, ctx->delta_scale);
 			}
 		}
 		
@@ -625,11 +625,11 @@ static void pimp_mod_context_update_tick(struct pimp_mod_context *ctx)
 		{
 			if (ctx->mod->flags & FLAG_LINEAR_PERIODS)
 			{
-				mc->sample_cursor_delta = pimp_get_linear_delta(chan->final_period);
+				mc->sample_cursor_delta = pimp_get_linear_delta(chan->final_period, ctx->delta_scale);
 			}
 			else
 			{
-				mc->sample_cursor_delta = pimp_get_amiga_delta(chan->final_period);
+				mc->sample_cursor_delta = pimp_get_amiga_delta(chan->final_period, ctx->delta_scale);
 			}
 		}
 		

testbench/Makefile

@@ -51,7 +51,4 @@ dump_render$(EXE_EXT): toplevel/dump_render.c $(TEST_DEPS_SOURCES)
 	$(LINK.cpp) $^$(LOADLIBES) $(LDLIBS) -o $@
 
 %.wav : %.sb
-	sox -r 18157 $< $@
-
-%.wav : %.ub
-	sox -r 18157 $< $@
+	sox -r 44100 $< $@
\ No newline at end of file

testbench/toplevel/dump_render.c

 #include "../../src/pimp_mod_context.h"
 #include "../../src/pimp_sample_bank.h"
 #include "../../src/pimp_render.h"
-#include "../../converter/load_module.h"
+#include "../../src/load_module.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -57,7 +57,7 @@ int main(int argc, char *argv[])
 
 	/* setup rendering */
 	mixer.mix_buffer = mixbuf;
-	pimp_mod_context_init(&ctx, mod, (const u8*)sample_bank.data, &mixer);
+	pimp_mod_context_init(&ctx, mod, (const u8*)sample_bank.data, &mixer, 44100.0f);
 	
 	/* render module to buffer */
 	pimp_render(&ctx, buf, SAMPLES);