88 lines
2.0 KiB
C++
88 lines
2.0 KiB
C++
/* libs/opengles/fp.cpp
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**
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** Copyright 2006, The Android Open Source Project
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**
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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**
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** http://www.apache.org/licenses/LICENSE-2.0
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**
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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*/
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#include "fp.h"
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// ----------------------------------------------------------------------------
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#if !defined(__arm__) && !defined(__mips__)
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GGLfixed gglFloatToFixed(float v) {
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return GGLfixed(floorf(v * 65536.0f + 0.5f));
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}
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#endif
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// ----------------------------------------------------------------------------
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namespace android {
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namespace gl {
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GLfloat fixedToFloat(GLfixed x)
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{
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#if DEBUG_USE_FLOATS
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return x / 65536.0f;
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#else
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if (!x) return 0;
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const uint32_t s = x & 0x80000000;
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union {
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uint32_t i;
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float f;
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};
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i = s ? -x : x;
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const int c = gglClz(i) - 8;
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i = (c>=0) ? (i<<c) : (i>>-c);
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const uint32_t e = 134 - c;
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i &= ~0x800000;
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i |= e<<23;
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i |= s;
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return f;
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#endif
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}
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float sinef(float x)
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{
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const float A = 1.0f / (2.0f*M_PI);
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const float B = -16.0f;
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const float C = 8.0f;
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// scale angle for easy argument reduction
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x *= A;
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if (fabsf(x) >= 0.5f) {
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// Argument reduction
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x = x - ceilf(x + 0.5f) + 1.0f;
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}
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const float y = B*x*fabsf(x) + C*x;
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return 0.2215f * (y*fabsf(y) - y) + y;
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}
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float cosinef(float x)
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{
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return sinef(x + float(M_PI/2));
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}
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void sincosf(GLfloat angle, GLfloat* s, GLfloat* c) {
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*s = sinef(angle);
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*c = cosinef(angle);
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}
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}; // namespace fp_utils
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// ----------------------------------------------------------------------------
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}; // namespace android
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