blob: aea44493e3121c8677283a42d87837088c11d511 [file] [log] [blame]
The Android Open Source Projectedbf3b62009-03-03 19:31:44 -08001/* libs/opengles/fp.cpp
2**
3** Copyright 2006, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9** http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18#include "fp.h"
19
20// ----------------------------------------------------------------------------
21
Duane Sandb43722c2013-03-27 10:53:14 -070022#if !defined(__arm__) && !defined(__mips__)
The Android Open Source Projectedbf3b62009-03-03 19:31:44 -080023GGLfixed gglFloatToFixed(float v) {
24 return GGLfixed(floorf(v * 65536.0f + 0.5f));
25}
26#endif
27
28// ----------------------------------------------------------------------------
29
30namespace android {
31
32namespace gl {
33
34GLfloat fixedToFloat(GLfixed x)
35{
36#if DEBUG_USE_FLOATS
37 return x / 65536.0f;
38#else
39 if (!x) return 0;
40 const uint32_t s = x & 0x80000000;
41 union {
42 uint32_t i;
43 float f;
44 };
45 i = s ? -x : x;
46 const int c = gglClz(i) - 8;
47 i = (c>=0) ? (i<<c) : (i>>-c);
48 const uint32_t e = 134 - c;
49 i &= ~0x800000;
50 i |= e<<23;
51 i |= s;
52 return f;
53#endif
54}
55
56float sinef(float x)
57{
58 const float A = 1.0f / (2.0f*M_PI);
59 const float B = -16.0f;
60 const float C = 8.0f;
61
62 // scale angle for easy argument reduction
63 x *= A;
64
65 if (fabsf(x) >= 0.5f) {
66 // Argument reduction
67 x = x - ceilf(x + 0.5f) + 1.0f;
68 }
69
70 const float y = B*x*fabsf(x) + C*x;
71 return 0.2215f * (y*fabsf(y) - y) + y;
72}
73
74float cosinef(float x)
75{
76 return sinef(x + float(M_PI/2));
77}
78
79void sincosf(GLfloat angle, GLfloat* s, GLfloat* c) {
80 *s = sinef(angle);
81 *c = cosinef(angle);
82}
83
84}; // namespace fp_utils
85
86// ----------------------------------------------------------------------------
87}; // namespace android