diff options
Diffstat (limited to 'system/pdp_resample.c')
| -rw-r--r-- | system/pdp_resample.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/system/pdp_resample.c b/system/pdp_resample.c new file mode 100644 index 0000000..2b5a9de --- /dev/null +++ b/system/pdp_resample.c @@ -0,0 +1,135 @@ +/* + * Pure Data Packet system file. - image resampling routines + * Copyright (c) by Tom Schouten <pdp@zzz.kotnet.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + + +#include "pdp_resample.h" +#include "pdp.h" + +/* + +efficient bilinear resampling ?? +performance: how to eliminate divides? -> virtual coordinates 2^k x 2^k (conf. opengl) + +i.e. 16 bit virtual coordinates: easy modular addressing + +*/ + +s32 pdp_resample_bilin(s16 *image, s32 width, s32 height, s32 virt_x, s32 virt_y) +{ + + s32 fp_x, fp_y, frac_x, frac_y, f, offset, r_1, r_2; + + virt_x &= 0xffff; + virt_y &= 0xffff; + + fp_x = virt_x * (width - 1); + fp_y = virt_y * (height - 1); + + frac_x = fp_x & (0xffff); + frac_y = fp_y & (0xffff); + + offset = (fp_x >> 16) + (fp_y >> 16) * width; + image += offset; + + f = 0x10000 - frac_x; + + r_1 = ((f * (s32)(image[0]) + frac_x * (s32)(image[1])))>>16; + + image += width; + + r_2 = ((f * (s32)(image[0]) + frac_x * (s32)(image[1])))>>16; + + f = 0x10000 - frac_y; + + return ((f * r_1 + frac_y * r_2)>>16); + +} + + +void pdp_resample_scale_bilin(s16 *src_image, s16 *dst_image, s32 src_w, s32 src_h, s32 dst_w, s32 dst_h) +{ + s32 i,j; + s32 virt_x=0; + s32 virt_y=0; /* virtual coordinates in 30 bit */ + s32 scale_x = 0x40000000 / dst_w; + s32 scale_y = 0x40000000 / dst_h; + + for (j=0; j<dst_h; j++){ + for (i=0; i<dst_w; i++){ + *dst_image++ = pdp_resample_bilin(src_image, src_w, src_h, virt_x>>14, virt_y>>14); + virt_x += scale_x; + } + virt_x = 0; + virt_y += scale_y; + } + +} + +void pdp_resample_scale_nn(s16 *src_image, s16 *dst_image, s32 src_w, s32 src_h, s32 dst_w, s32 dst_h) +{ + s32 i,j; + s32 x=0; + s32 y=0; + s32 frac_x=0; + s32 frac_y=0; + s32 scale_x = (src_w << 20 ) / dst_w; + s32 scale_y = (src_h << 20 ) / dst_h; + + for (j=0; j<dst_h; j++){ + for (i=0; i<dst_w; i++){ + *dst_image++ = src_image[x+y]; + frac_x += scale_x; + x = frac_x >> 20; + } + x = 0; + frac_x = 0; + frac_y += scale_y; + y = (frac_y >> 20) * src_w; + } + +} + +void pdp_resample_zoom_tiled_bilin(s16 *src_image, s16 *dst_image, s32 w, s32 h, + float zoom_x, float zoom_y, float center_x_relative, float center_y_relative) +{ + float izx = 1.0f / zoom_x; + float izy = 1.0f / zoom_y; + s32 scale_x = (s32)((float)0x100000 * izx / (float)w); + s32 scale_y = (s32)((float)0x100000 * izy / (float)h); + + s32 top_virt_x = (s32)((1.0f - izx) * (float)0x100000 * center_x_relative); + s32 top_virt_y = (s32)((1.0f - izy) * (float)0x100000 * center_y_relative); + + s32 virt_x = top_virt_x; + s32 virt_y = top_virt_y; + + s32 i,j; + + for (j=0; j<h; j++){ + for (i=0; i<w; i++){ + *dst_image++ = pdp_resample_bilin(src_image, w, h, virt_x>>4, virt_y>>4); + virt_x += scale_x; + } + virt_x = top_virt_x; + virt_y += scale_y; + } + +} + |