The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* 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 Sand | b43722c | 2013-03-27 10:53:14 -0700 | [diff] [blame] | 22 | #if !defined(__arm__) && !defined(__mips__) |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 23 | GGLfixed gglFloatToFixed(float v) { |
| 24 | return GGLfixed(floorf(v * 65536.0f + 0.5f)); |
| 25 | } |
| 26 | #endif |
| 27 | |
| 28 | // ---------------------------------------------------------------------------- |
| 29 | |
| 30 | namespace android { |
| 31 | |
| 32 | namespace gl { |
| 33 | |
| 34 | GLfloat 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 | |
| 56 | float 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 | |
| 74 | float cosinef(float x) |
| 75 | { |
| 76 | return sinef(x + float(M_PI/2)); |
| 77 | } |
| 78 | |
| 79 | void 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 |