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Diffstat (limited to 'android/skin/scaler.c')
| -rw-r--r-- | android/skin/scaler.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/android/skin/scaler.c b/android/skin/scaler.c new file mode 100644 index 0000000..59e212f --- /dev/null +++ b/android/skin/scaler.c @@ -0,0 +1,135 @@ +/* Copyright (C) 2008 The Android Open Source Project +** +** This software is licensed under the terms of the GNU General Public +** License version 2, as published by the Free Software Foundation, and +** may be copied, distributed, and modified under those terms. +** +** This program is distributed in the hope that it will be useful, +** but WITHOUT ANY WARRANTY; without even the implied warranty of +** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +** GNU General Public License for more details. +*/ +#include "android/skin/scaler.h" +#include <stdint.h> +#include <math.h> + +struct SkinScaler { + double scale; + double xdisp, ydisp; + double invscale; + int valid; +}; + +static SkinScaler _scaler0; + +SkinScaler* +skin_scaler_create( void ) +{ + _scaler0.scale = 1.0; + _scaler0.xdisp = 0.0; + _scaler0.ydisp = 0.0; + _scaler0.invscale = 1.0; + return &_scaler0; +} + +/* change the scale of a given scaler. returns 0 on success, or -1 in case of + * problem (unsupported scale) */ +int +skin_scaler_set( SkinScaler* scaler, double scale, double xdisp, double ydisp ) +{ + /* right now, we only support scales in the 0.5 .. 1.0 range */ + if (scale < 0.1) + scale = 0.1; + else if (scale > 6.0) + scale = 6.0; + + scaler->scale = scale; + scaler->xdisp = xdisp; + scaler->ydisp = ydisp; + scaler->invscale = 1/scale; + scaler->valid = 1; + + return 0; +} + +void +skin_scaler_free( SkinScaler* scaler ) +{ + scaler=scaler; +} + +typedef struct { + SDL_Rect rd; /* destination rectangle */ + int sx, sy; /* source start position in 16.16 format */ + int ix, iy; /* source increments in 16.16 format */ + int src_pitch; + int src_w; + int src_h; + int dst_pitch; + uint8_t* dst_line; + uint8_t* src_line; + double scale; +} ScaleOp; + + +#define ARGB_SCALE_GENERIC scale_generic +#define ARGB_SCALE_05_TO_10 scale_05_to_10 +#define ARGB_SCALE_UP_BILINEAR scale_up_bilinear +#define ARGB_SCALE_UP_QUICK_4x4 scale_up_quick_4x4 + +#include "android/skin/argb.h" + + +void +skin_scaler_scale( SkinScaler* scaler, + SDL_Surface* dst_surface, + SDL_Surface* src_surface, + int sx, + int sy, + int sw, + int sh ) +{ + ScaleOp op; + + if ( !scaler->valid ) + return; + + SDL_LockSurface( src_surface ); + SDL_LockSurface( dst_surface ); + { + op.scale = scaler->scale; + op.src_pitch = src_surface->pitch; + op.src_line = src_surface->pixels; + op.src_w = src_surface->w; + op.src_h = src_surface->h; + op.dst_pitch = dst_surface->pitch; + op.dst_line = dst_surface->pixels; + + /* compute the destination rectangle */ + op.rd.x = (int)(sx * scaler->scale + scaler->xdisp); + op.rd.y = (int)(sy * scaler->scale + scaler->ydisp); + op.rd.w = (int)(ceil((sx + sw) * scaler->scale + scaler->xdisp)) - op.rd.x; + op.rd.h = (int)(ceil((sy + sh) * scaler->scale + scaler->ydisp)) - op.rd.y; + + /* compute the starting source position in 16.16 format + * and the corresponding increments */ + op.sx = (int)((op.rd.x - scaler->xdisp) * scaler->invscale * 65536); + op.sy = (int)((op.rd.y - scaler->ydisp) * scaler->invscale * 65536); + + op.ix = (int)( scaler->invscale * 65536 ); + op.iy = op.ix; + + op.dst_line += op.rd.x*4 + op.rd.y*op.dst_pitch; + + if (op.scale >= 0.5 && op.scale <= 1.0) + scale_05_to_10( &op ); + else if (op.scale > 1.0) + scale_up_bilinear( &op ); + else + scale_generic( &op ); + } + SDL_UnlockSurface( dst_surface ); + SDL_UnlockSurface( src_surface ); + + SDL_UpdateRects( dst_surface, 1, &op.rd ); +} |