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 22 #if !defined(__arm__) && !defined(__mips__) gglFloatToFixed(float v)23GGLfixed 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 fixedToFloat(GLfixed x)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 sinef(float x)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 cosinef(float x)74float cosinef(float x) 75 { 76 return sinef(x + float(M_PI/2)); 77 } 78 sincosf(GLfloat angle,GLfloat * s,GLfloat * c)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 88