(svn r13354) -Codechange: make 8bpp_optimized blitter ~25% faster in encoding and ~15% faster in drawing (depends on architecture)
/* $Id$ */
/** @file 8bpp_optimized.cpp Implementation of the optimized 8 bpp blitter. */
#include "../stdafx.h"
#include "../zoom_func.h"
#include "../debug.h"
#include "../core/alloc_func.hpp"
#include "../core/math_func.hpp"
#include "8bpp_optimized.hpp"
static FBlitter_8bppOptimized iFBlitter_8bppOptimized;
void Blitter_8bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
{
/* Find the offset of this zoom-level */
uint offset = ((const uint8 *)bp->sprite)[(int)(zoom - ZOOM_LVL_BEGIN) * 2] | ((const byte *)bp->sprite)[(int)(zoom - ZOOM_LVL_BEGIN) * 2 + 1] << 8;
/* Find where to start reading in the source sprite */
const uint8 *src = (const uint8 *)bp->sprite + offset;
uint8 *dst_line = (uint8 *)bp->dst + bp->top * bp->pitch + bp->left;
/* Skip over the top lines in the source image */
for (int y = 0; y < bp->skip_top; y++) {
for (;;) {
uint trans = *src++;
uint pixels = *src++;
if (trans == 0 && pixels == 0) break;
src += pixels;
}
}
const uint8 *src_next = src;
for (int y = 0; y < bp->height; y++) {
uint8 *dst = dst_line;
dst_line += bp->pitch;
uint skip_left = bp->skip_left;
int width = bp->width;
for (;;) {
src = src_next;
uint trans = *src++;
uint pixels = *src++;
src_next = src + pixels;
if (trans == 0 && pixels == 0) break;
if (width <= 0) continue;
if (skip_left != 0) {
if (skip_left < trans) {
trans -= skip_left;
skip_left = 0;
} else {
skip_left -= trans;
trans = 0;
}
if (skip_left < pixels) {
src += skip_left;
pixels -= skip_left;
skip_left = 0;
} else {
src += pixels;
skip_left -= pixels;
pixels = 0;
}
}
if (skip_left != 0) continue;
/* Skip transparent pixels */
dst += trans;
width -= trans;
if (width <= 0) continue;
pixels = min<uint>(pixels, (uint)width);
width -= pixels;
switch (mode) {
case BM_COLOUR_REMAP:
for (uint x = 0; x < pixels; x++) {
if (bp->remap[*src] != 0) *dst = bp->remap[*src];
dst++; src++;
}
break;
case BM_TRANSPARENT:
for (uint x = 0; x < pixels; x++) {
*dst = bp->remap[*dst];
dst++; src++;
}
break;
default:
memcpy(dst, src, pixels);
dst += pixels; src += pixels;
break;
}
}
}
}
Sprite *Blitter_8bppOptimized::Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator)
{
/* Make memory for all zoom-levels */
uint memory = (int)(ZOOM_LVL_END - ZOOM_LVL_BEGIN) * sizeof(uint16);
for (ZoomLevel i = ZOOM_LVL_BEGIN; i < ZOOM_LVL_END; i++) {
memory += UnScaleByZoom(sprite->height, i) * UnScaleByZoom(sprite->width, i);
}
/* We have no idea how much memory we really need, so just guess something */
memory *= 5;
byte *temp_dst = MallocT<byte>(memory);
byte *dst = &temp_dst[(ZOOM_LVL_END - ZOOM_LVL_BEGIN) * 2];
/* Make the sprites per zoom-level */
for (ZoomLevel i = ZOOM_LVL_BEGIN; i < ZOOM_LVL_END; i++) {
/* Store the index table */
uint index = dst - temp_dst;
temp_dst[i * 2] = index & 0xFF;
temp_dst[i * 2 + 1] = (index >> 8) & 0xFF;
/* cache values, because compiler can't cache it */
int scaled_height = UnScaleByZoom(sprite->height, i);
int scaled_width = UnScaleByZoom(sprite->width, i);
int scaled_1 = ScaleByZoom(1, i);
for (int y = 0; y < scaled_height; y++) {
uint trans = 0;
uint pixels = 0;
uint last_colour = 0;
byte *count_dst = NULL;
/* Store the scaled image */
const SpriteLoader::CommonPixel *src = &sprite->data[ScaleByZoom(y, i) * sprite->width];
const SpriteLoader::CommonPixel *src_end = &src[sprite->width];
for (int x = 0; x < scaled_width; x++) {
uint colour = 0;
/* Get the color keeping in mind the zoom-level */
for (int j = 0; j < scaled_1; j++) {
if (src->m != 0) colour = src->m;
/* Because of the scaling it might happen we read outside the buffer. Avoid that. */
if (++src == src_end) break;
}
if (last_colour == 0 || colour == 0 || pixels == 255) {
if (count_dst != NULL) {
/* Write how many non-transparent bytes we get */
*count_dst = pixels;
pixels = 0;
count_dst = NULL;
}
/* As long as we find transparency bytes, keep counting */
if (colour == 0) {
last_colour = 0;
trans++;
continue;
}
/* No longer transparency, so write the amount of transparent bytes */
*dst = trans;
dst++;
trans = 0;
/* Reserve a byte for the pixel counter */
count_dst = dst;
dst++;
}
last_colour = colour;
pixels++;
*dst = colour;
dst++;
}
if (count_dst != NULL) *count_dst = pixels;
/* Write line-ending */
*dst = 0; dst++;
*dst = 0; dst++;
}
}
uint size = dst - temp_dst;
/* Safety check, to make sure we guessed the size correctly */
assert(size < memory);
/* Allocate the exact amount of memory we need */
Sprite *dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite) + size);
dest_sprite->height = sprite->height;
dest_sprite->width = sprite->width;
dest_sprite->x_offs = sprite->x_offs;
dest_sprite->y_offs = sprite->y_offs;
memcpy(dest_sprite->data, temp_dst, size);
free(temp_dst);
return dest_sprite;
}