From 5c1676dfe6d2f3c837a5e074117b45613fd29a72 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:30:19 +0200 Subject: Adding upstream version 2.10.34. Signed-off-by: Daniel Baumann --- tools/kernelgen.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 tools/kernelgen.c (limited to 'tools/kernelgen.c') diff --git a/tools/kernelgen.c b/tools/kernelgen.c new file mode 100644 index 0000000..e2d8ef0 --- /dev/null +++ b/tools/kernelgen.c @@ -0,0 +1,128 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995 Spencer Kimball and Peter Mattis + * + * kernelgen -- Copyright (C) 2000 Sven Neumann + * + * Simple hack to create brush subsampling kernels. If you want to + * play with it, change some of the #defines at the top and copy + * the output to app/paint/gimpbrushcore-kernels.h. + * + * 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 3 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, see . + */ + +#include +#include +#include + + +#define STEPS 64 +#define KERNEL_WIDTH 3 /* changing these makes no sense */ +#define KERNEL_HEIGHT 3 /* changing these makes no sense */ +#define KERNEL_SUM 256 +#define SUBSAMPLE 4 +#define THRESHOLD 0.25 /* try to change this one */ + +#define SQR(x) ((x) * (x)) + +static void +create_kernel (double x, + double y) +{ + double value[KERNEL_WIDTH][KERNEL_HEIGHT]; + double dist_x; + double dist_y; + double sum; + double w; + int i, j; + + memset (value, 0, KERNEL_WIDTH * KERNEL_HEIGHT * sizeof (double)); + sum = 0.0; + + x += 1.0; + y += 1.0; + + for (j = 0; j < STEPS * KERNEL_HEIGHT; j++) + { + dist_y = y - (((double)j + 0.5) / (double)STEPS); + + for (i = 0; i < STEPS * KERNEL_WIDTH; i++) + { + dist_x = x - (((double) i + 0.5) / (double) STEPS); + + /* I've tried to use a gauss function here instead of a + threshold, but the result was not that impressive. */ + w = (SQR (dist_x) + SQR (dist_y)) < THRESHOLD ? 1.0 : 0.0; + + value[i / STEPS][j / STEPS] += w; + sum += w; + } + } + + for (j = 0; j < KERNEL_HEIGHT; j++) + { + for (i = 0; i < KERNEL_WIDTH; i++) + { + w = (double) KERNEL_SUM * value[i][j] / sum; + printf (" %3d,", (int) (w + 0.5)); + } + } +} + +int +main (int argc, + char **argv) +{ + int i, j; + double x, y; + + printf ("/* gimpbrushcore-kernels.h\n" + " *\n" + " * This file was generated using kernelgen as found in the tools dir.\n"); + printf (" * (threshold = %g)\n", THRESHOLD); + printf (" */\n\n"); + printf ("#ifndef __GIMP_BRUSH_CORE_KERNELS_H__\n"); + printf ("#define __GIMP_BRUSH_CORE_KERNELS_H__\n\n"); + printf ("#define KERNEL_WIDTH %d\n", KERNEL_WIDTH); + printf ("#define KERNEL_HEIGHT %d\n", KERNEL_HEIGHT); + printf ("#define KERNEL_SUBSAMPLE %d\n", SUBSAMPLE); + printf ("#define KERNEL_SUM %d\n", KERNEL_SUM); + printf ("\n\n"); + printf ("/* Brush pixel subsampling kernels */\n"); + printf ("static const int subsample[%d][%d][%d] =\n{\n", + SUBSAMPLE + 1, SUBSAMPLE + 1, KERNEL_WIDTH * KERNEL_HEIGHT); + + for (j = 0; j <= SUBSAMPLE; j++) + { + y = (double) j / (double) SUBSAMPLE; + + printf (" {\n"); + + for (i = 0; i <= SUBSAMPLE; i++) + { + x = (double) i / (double) SUBSAMPLE; + + printf (" {"); + create_kernel (x, y); + printf (" }%s", i < SUBSAMPLE ? ",\n" : "\n"); + } + + printf (" }%s", j < SUBSAMPLE ? ",\n" : "\n"); + } + + printf ("};\n\n"); + + printf ("#endif /* __GIMP_BRUSH_CORE_KERNELS_H__ */\n"); + + return 0; +} -- cgit v1.2.3