mirror of
https://github.com/KolibriOS/kolibrios.git
synced 2024-12-24 07:36:48 +03:00
159 lines
3.5 KiB
C
159 lines
3.5 KiB
C
/*
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* This file is part of LibCSS.
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* Licensed under the MIT License,
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* http://www.opensource.org/licenses/mit-license.php
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* Copyright 2008 John-Mark Bell <jmb@netsurf-browser.org>
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*/
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#ifndef libcss_fpmath_h_
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#define libcss_fpmath_h_
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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#include <stdint.h>
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#include <limits.h>
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/* 22:10 fixed point math */
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#define CSS_RADIX_POINT 10
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/* type for fixed point numbers */
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typedef int32_t css_fixed;
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static inline css_fixed
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css_add_fixed(const css_fixed x, const css_fixed y) {
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int32_t ux = x;
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int32_t uy = y;
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int32_t res = ux + uy;
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/* Calculate overflowed result. (Don't change the sign bit of ux) */
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ux = (ux >> 31) + INT_MAX;
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/* Force compiler to use cmovns instruction */
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if ((int32_t) ((ux ^ uy) | ~(uy ^ res)) >= 0) {
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res = ux;
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}
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return res;
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}
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static inline css_fixed
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css_subtract_fixed(const css_fixed x, const css_fixed y) {
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int32_t ux = x;
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int32_t uy = y;
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int32_t res = ux - uy;
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ux = (ux >> 31) + INT_MAX;
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/* Force compiler to use cmovns instruction */
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if ((int32_t)((ux ^ uy) & (ux ^ res)) < 0) {
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res = ux;
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}
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return res;
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}
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static inline css_fixed
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css_divide_fixed(const css_fixed x, const css_fixed y) {
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int64_t xx = ((int64_t)x << CSS_RADIX_POINT) / y;
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if (xx < INT_MIN)
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xx = INT_MIN;
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if (xx > INT_MAX)
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xx = INT_MAX;
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return xx;
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}
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static inline css_fixed
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css_multiply_fixed(const css_fixed x, const css_fixed y) {
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int64_t xx = ((int64_t)x * (int64_t)y) >> CSS_RADIX_POINT;
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if (xx < INT_MIN)
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xx = INT_MIN;
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if (xx > INT_MAX)
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xx = INT_MAX;
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return xx;
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}
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static inline css_fixed
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css_int_to_fixed(const int a) {
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int64_t xx = ((int64_t) a) << CSS_RADIX_POINT;
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if (xx < INT_MIN)
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xx = INT_MIN;
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if (xx > INT_MAX)
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xx = INT_MAX;
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return xx;
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}
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static inline css_fixed
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css_float_to_fixed(const float a) {
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float xx = a * (float) (1 << CSS_RADIX_POINT);
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if (xx < INT_MIN)
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xx = INT_MIN;
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if (xx > INT_MAX)
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xx = INT_MAX;
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return (css_fixed) xx;
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}
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/* Add two fixed point values */
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#define FADD(a, b) (css_add_fixed((a), (b)))
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/* Subtract two fixed point values */
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#define FSUB(a, b) (css_subtract_fixed((a), (b)))
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/* Multiply two fixed point values */
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#define FMUL(a, b) (css_multiply_fixed((a), (b)))
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/* Divide two fixed point values */
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#define FDIV(a, b) (css_divide_fixed((a), (b)))
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/* Convert a floating point value to fixed point */
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#define FLTTOFIX(a) ((css_fixed) ((a) * (float) (1 << CSS_RADIX_POINT)))
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/* Convert a fixed point value to floating point */
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#define FIXTOFLT(a) ((float) (a) / (float) (1 << CSS_RADIX_POINT))
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/* Convert an integer to a fixed point value */
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#define INTTOFIX(a) (css_int_to_fixed(a))
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/* Convert a fixed point value to an integer */
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#define FIXTOINT(a) ((a) >> CSS_RADIX_POINT)
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/* truncate a fixed point value */
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#define TRUNCATEFIX(a) (a & ~((1 << CSS_RADIX_POINT)- 1 ))
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/* Useful values */
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#define F_PI_2 0x00000648 /* 1.5708 (PI/2) */
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#define F_PI 0x00000c91 /* 3.1415 (PI) */
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#define F_3PI_2 0x000012d9 /* 4.7124 (3PI/2) */
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#define F_2PI 0x00001922 /* 6.2831 (2 PI) */
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#define F_90 0x00016800 /* 90 */
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#define F_180 0x0002d000 /* 180 */
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#define F_270 0x00043800 /* 270 */
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#define F_360 0x0005a000 /* 360 */
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#define F_0_5 0x00000200 /* 0.5 */
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#define F_1 0x00000400 /* 1 */
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#define F_10 0x00002800 /* 10 */
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#define F_72 0x00012000 /* 72 */
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#define F_100 0x00019000 /* 100 */
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#define F_200 0x00032000 /* 200 */
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#define F_255 0x0003FC00 /* 255 */
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#define F_300 0x0004b000 /* 300 */
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#define F_400 0x00064000 /* 400 */
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#ifdef __cplusplus
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}
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#endif
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#endif
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