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DSS_COUNTER updates

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- clock_node no longer needs to be static for DISC_CLK_IS_FREQ
- rewrote inc/dec logic to avoid loop
This commit is contained in:
Couriersud 2009-08-15 12:56:48 +00:00
parent 1f4ecb37a3
commit 3874ecc65c
2 changed files with 12 additions and 15 deletions
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24
src/emu/sound/disc_wav.c
View File

@ -35,7 +35,6 @@ struct dss_counter_context
int is_7492;
int last; /* Last clock state */
int count; /* current count */
double t_clock; /* fixed counter clock in seconds */
double t_left; /* time unused during last sample in seconds */
};
@ -185,6 +184,7 @@ static DISCRETE_STEP(dss_counter)
{
struct dss_counter_context *context = (struct dss_counter_context *)node->context;
double cycles;
double ds_clock;
int clock = 0, last_count, inc = 0;
int max;
double x_time = 0;
@ -194,18 +194,19 @@ static DISCRETE_STEP(dss_counter)
else
max = DSS_COUNTER__MAX;
ds_clock = DSS_COUNTER__CLOCK;
if (context->clock_type == DISC_CLK_IS_FREQ)
{
/* We need to keep clocking the internal clock even if disabled. */
cycles = (context->t_left + disc_info->sample_time) / context->t_clock;
cycles = (context->t_left + disc_info->sample_time) * ds_clock;
inc = (int)cycles;
context->t_left = (cycles - inc) * context->t_clock;
context->t_left = (cycles - inc) / ds_clock;
if (inc) x_time = context->t_left / disc_info->sample_time;
}
else
{
clock = (int)DSS_COUNTER__CLOCK;
x_time = DSS_COUNTER__CLOCK - clock;
clock = (int)ds_clock;
x_time = ds_clock - clock;
}
@ -242,18 +243,16 @@ static DISCRETE_STEP(dss_counter)
}
break;
case DISC_CLK_BY_COUNT:
case DISC_CLK_BY_COUNT:
/* Clock number of times specified. */
inc = clock;
break;
}
for (clock = 0; clock < inc; clock++)
{
context->count += DSS_COUNTER__DIR ? 1 : -1; /* up/down */
if (context->count < 0) context->count = max;
if (context->count > max) context->count = 0;
}
if (DSS_COUNTER__DIR)
context->count = (context->count + inc) % (max + 1);
else
context->count = max - ((context->count + inc) % (max + 1));
node->output[0] = context->is_7492 ? disc_7492_count[context->count] : context->count;
@ -297,7 +296,6 @@ static DISCRETE_RESET(dss_counter)
context->out_type = context->clock_type & DISC_OUT_MASK;
context->clock_type &= DISC_CLK_MASK;
context->t_clock = 1.0 / DSS_COUNTER__CLOCK;
context->t_left = 0;
context->last = 0;
context->count = DSS_COUNTER__INIT; /* count starts at reset value */

3
src/emu/sound/discrete.h
View File

@ -461,8 +461,7 @@
* DISC_CLK_ON_R_EDGE - toggle on rising edge.
* DISC_CLK_BY_COUNT - toggle specified number of times.
* DISC_CLK_IS_FREQ - internally clock at this frequency.
* Clock node must be static if
* DISC_CLK_IS_FREQ is used.
*
* x_time options: you can also | these x_time features to the basic
* types above if needed, or use seperately with 7492.
* DISC_OUT_IS_ENERGY - This will uses the x_time to