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scaler optimizations:

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on sh, use 8.24 fixed-point C math for final division in scaler

on coldfire, use 8.32 fixed-point via emac

on other architectures, use 8.32 fixed-point C math

use shift-and-add to divide when adjusting scale factors in pictureflow

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19802 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andrew Mahone 2009-01-20 17:24:49 +00:00
parent 73f2d001fd
commit 1b13299769
3 changed files with 66 additions and 22 deletions
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22
apps/plugins/pictureflow.c
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@ -397,8 +397,8 @@ static inline PFreal fcos(int iangle)
return fsin(iangle + (IANGLE_MAX >> 2));
}
#define RB_DIV ((31ULL << 32) / 255 + 1)
#define G_DIV ((63ULL << 32) / 255 + 1)
#define DIV255(val) ((((((val)>>8)+(val))>>8)+(val))>>8)
#define SCALE_VAL(val,out) DIV255((val) * (out) + 127)
static void output_row_transposed(uint32_t row, void * row_in,
struct scaler_context *ctx)
@ -408,19 +408,19 @@ static void output_row_transposed(uint32_t row, void * row_in,
#ifdef USEGSLIB
uint32_t *qp = (uint32_t*)row_in;
for (; dest < end; dest += ctx->bm->height)
*dest = ((*qp++) + ctx->round) * (uint64_t)ctx->divisor >> 32;
*dest = SC_MUL((*qp++) + ctx->round), ctx->divisor);
#else
struct uint32_rgb *qp = (struct uint32_rgb*)row_in;
uint32_t rb_mul = ctx->divisor * (uint64_t)RB_DIV >> 32,
rb_rnd = ctx->round * (uint64_t)RB_DIV >> 32,
g_mul = ctx->divisor * (uint64_t)G_DIV >> 32,
g_rnd = ctx->round * (uint64_t)G_DIV >> 32;
int r, g, b;
uint32_t rb_mul = SCALE_VAL(ctx->divisor, 31),
rb_rnd = SCALE_VAL(ctx->round, 31),
g_mul = SCALE_VAL(ctx->divisor, 63),
g_rnd = SCALE_VAL(ctx->round, 63);
int r, g, b;
for (; dest < end; dest += ctx->bm->height)
{
r = (qp->r + rb_rnd) * (uint64_t)rb_mul >> 32;
g = (qp->g + g_rnd) * (uint64_t)g_mul >> 32;
b = (qp->b + rb_rnd) * (uint64_t)rb_mul >> 32;
r = SC_MUL(qp->r + rb_rnd, rb_mul);
g = SC_MUL(qp->g + g_rnd, g_mul);
b = SC_MUL(qp->b + rb_rnd, rb_mul);
qp++;
*dest = LCD_RGBPACK_LCD(r,g,b);
}