devs/foxbox
1
0
Fork 0
forked from len0rd/rockbox
Code Pull requests Activity

Mandelbrot: * Asm optimisation for arm targets. * Proper aspect for all LCD resolutions. * Keep proper aspect when zooming on targets where LCD_WIDTH and/or LCD_HEIGHT is not an integer multiple of 8.

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10498 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2006-08-09 12:04:04 +00:00
parent 8d642c302d
commit 0f87f8fd36
1 changed files with 45 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

58
apps/plugins/mandelbrot.c
View file

@ -135,7 +135,7 @@ PLUGIN_HEADER
static struct plugin_api* rb;
/* Fixed point format: 6 bits integer part incl. sign, 26 bits fractional part */
/* Fixed point format s5.26: sign, 5 bits integer part, 26 bits fractional part */
static long x_min;
static long x_max;
static long x_step;
@ -291,10 +291,30 @@ static inline long muls32_asr26(long a, long b)
return r;
}
#elif defined CPU_ARM
#define MULS32_ASR26(a, b) muls32_asr26(a, b)
static inline long muls32_asr26(long a, long b)
{
long r, t1;
asm (
"smull %[r], %[t1], %[a], %[b] \n"
"mov %[r], %[r], lsr #26 \n"
"orr %[r], %[r], %[t1], lsl #6 \n"
: /* outputs */
[r] "=&r"(r),
[t1]"=&r"(t1)
: /* inputs */
[a] "r" (a),
[b] "r" (b)
);
return r;
}
#endif /* CPU */
/* default macros */
#ifndef MULS16_ASR10
#ifndef MULS16_ASR10
#define MULS16_ASR10(a, b) ((short)(((long)(a) * (long)(b)) >> 10))
#endif
#ifndef MULS32_ASR26
@ -327,24 +347,36 @@ int ilog2_fp(long value) /* calculate integer log2(value_fp_6.26) */
void recalc_parameters(void)
{
x_step = (x_max - x_min) / LCD_WIDTH;
x_delta = x_step * (LCD_WIDTH/8);
x_delta = (x_step * LCD_WIDTH) / 8;
y_step = (y_max - y_min) / LCD_HEIGHT;
y_delta = y_step * (LCD_HEIGHT/8);
y_delta = (y_step * LCD_HEIGHT) / 8;
step_log2 = ilog2_fp(MIN(x_step, y_step));
max_iter = MAX(15, -15 * step_log2 - 45);
}
#if CONFIG_LCD == LCD_SSD1815
/* Recorder, Ondio: pixel_height == 1.25 * pixel_width */
#define MB_HEIGHT (LCD_HEIGHT*5/4)
#else
/* square pixels */
#define MB_HEIGHT LCD_HEIGHT
#endif
#define MB_XOFS (-0x03000000L) /* -0.75 (s5.26) */
#if 3000*MB_HEIGHT/LCD_WIDTH >= 2400 /* width is limiting factor */
#define MB_XFAC (0x06000000LL) /* 1.5 (s5.26) */
#define MB_YFAC (MB_XFAC*MB_HEIGHT/LCD_WIDTH)
#else /* height is limiting factor */
#define MB_YFAC (0x04cccccdLL) /* 1.2 (s5.26) */
#define MB_XFAC (MB_YFAC*LCD_WIDTH/MB_HEIGHT)
#endif
void init_mandelbrot_set(void)
{
#if CONFIG_LCD == LCD_SSD1815 /* Recorder, Ondio. */
x_min = -38L<<22; /* -2.375<<26 */
x_max = 15L<<22; /* 0.9375<<26 */
#else /* all others (square pixels) */
x_min = -36L<<22; /* -2.25<<26 */
x_max = 12L<<22; /* 0.75<<26 */
#endif
y_min = -19L<<22; /* -1.1875<<26 */
y_max = 19L<<22; /* 1.1875<<26 */
x_min = MB_XOFS-MB_XFAC;
x_max = MB_XOFS+MB_XFAC;
y_min = -MB_YFAC;
y_max = MB_YFAC;
recalc_parameters();
}