| /* 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 UNUSED */ |
| |
| #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 ); |
| } |