1 /* Copyright (C) 2008 The Android Open Source Project 2 ** 3 ** This software is licensed under the terms of the GNU General Public 4 ** License version 2, as published by the Free Software Foundation, and 5 ** may be copied, distributed, and modified under those terms. 6 ** 7 ** This program is distributed in the hope that it will be useful, 8 ** but WITHOUT ANY WARRANTY; without even the implied warranty of 9 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 ** GNU General Public License for more details. 11 */ 12 #include "android/skin/scaler.h" 13 #include <stdint.h> 14 #include <math.h> 15 16 struct SkinScaler { 17 double scale; 18 double xdisp, ydisp; 19 double invscale; 20 int valid; 21 }; 22 23 static SkinScaler _scaler0; 24 25 SkinScaler* 26 skin_scaler_create( void ) 27 { 28 _scaler0.scale = 1.0; 29 _scaler0.xdisp = 0.0; 30 _scaler0.ydisp = 0.0; 31 _scaler0.invscale = 1.0; 32 return &_scaler0; 33 } 34 35 /* change the scale of a given scaler. returns 0 on success, or -1 in case of 36 * problem (unsupported scale) */ 37 int 38 skin_scaler_set( SkinScaler* scaler, double scale, double xdisp, double ydisp ) 39 { 40 /* right now, we only support scales in the 0.5 .. 1.0 range */ 41 if (scale < 0.1) 42 scale = 0.1; 43 else if (scale > 6.0) 44 scale = 6.0; 45 46 scaler->scale = scale; 47 scaler->xdisp = xdisp; 48 scaler->ydisp = ydisp; 49 scaler->invscale = 1/scale; 50 scaler->valid = 1; 51 52 return 0; 53 } 54 55 void 56 skin_scaler_free( SkinScaler* scaler ) 57 { 58 scaler=scaler; 59 } 60 61 typedef struct { 62 SDL_Rect rd; /* destination rectangle */ 63 int sx, sy; /* source start position in 16.16 format */ 64 int ix, iy; /* source increments in 16.16 format */ 65 int src_pitch; 66 int src_w; 67 int src_h; 68 int dst_pitch; 69 uint8_t* dst_line; 70 uint8_t* src_line; 71 double scale; 72 } ScaleOp; 73 74 75 #define ARGB_SCALE_GENERIC scale_generic 76 #define ARGB_SCALE_05_TO_10 scale_05_to_10 77 #define ARGB_SCALE_UP_BILINEAR scale_up_bilinear 78 #define ARGB_SCALE_UP_QUICK_4x4 scale_up_quick_4x4 79 80 #include "android/skin/argb.h" 81 82 83 void 84 skin_scaler_scale( SkinScaler* scaler, 85 SDL_Surface* dst_surface, 86 SDL_Surface* src_surface, 87 int sx, 88 int sy, 89 int sw, 90 int sh ) 91 { 92 ScaleOp op; 93 94 if ( !scaler->valid ) 95 return; 96 97 SDL_LockSurface( src_surface ); 98 SDL_LockSurface( dst_surface ); 99 { 100 op.scale = scaler->scale; 101 op.src_pitch = src_surface->pitch; 102 op.src_line = src_surface->pixels; 103 op.src_w = src_surface->w; 104 op.src_h = src_surface->h; 105 op.dst_pitch = dst_surface->pitch; 106 op.dst_line = dst_surface->pixels; 107 108 /* compute the destination rectangle */ 109 op.rd.x = (int)(sx * scaler->scale + scaler->xdisp); 110 op.rd.y = (int)(sy * scaler->scale + scaler->ydisp); 111 op.rd.w = (int)(ceil((sx + sw) * scaler->scale + scaler->xdisp)) - op.rd.x; 112 op.rd.h = (int)(ceil((sy + sh) * scaler->scale + scaler->ydisp)) - op.rd.y; 113 114 /* compute the starting source position in 16.16 format 115 * and the corresponding increments */ 116 op.sx = (int)((op.rd.x - scaler->xdisp) * scaler->invscale * 65536); 117 op.sy = (int)((op.rd.y - scaler->ydisp) * scaler->invscale * 65536); 118 119 op.ix = (int)( scaler->invscale * 65536 ); 120 op.iy = op.ix; 121 122 op.dst_line += op.rd.x*4 + op.rd.y*op.dst_pitch; 123 124 if (op.scale >= 0.5 && op.scale <= 1.0) 125 scale_05_to_10( &op ); 126 else if (op.scale > 1.0) 127 scale_up_bilinear( &op ); 128 else 129 scale_generic( &op ); 130 } 131 SDL_UnlockSurface( dst_surface ); 132 SDL_UnlockSurface( src_surface ); 133 134 SDL_UpdateRects( dst_surface, 1, &op.rd ); 135 } 136