M7350/base/opengl/libagl/fp.cpp

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2024-09-09 08:52:07 +00:00
/* libs/opengles/fp.cpp
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include "fp.h"
// ----------------------------------------------------------------------------
#if !defined(__arm__)
GGLfixed gglFloatToFixed(float v) {
return GGLfixed(floorf(v * 65536.0f + 0.5f));
}
#endif
// ----------------------------------------------------------------------------
namespace android {
namespace gl {
GLfloat fixedToFloat(GLfixed x)
{
#if DEBUG_USE_FLOATS
return x / 65536.0f;
#else
if (!x) return 0;
const uint32_t s = x & 0x80000000;
union {
uint32_t i;
float f;
};
i = s ? -x : x;
const int c = gglClz(i) - 8;
i = (c>=0) ? (i<<c) : (i>>-c);
const uint32_t e = 134 - c;
i &= ~0x800000;
i |= e<<23;
i |= s;
return f;
#endif
}
float sinef(float x)
{
const float A = 1.0f / (2.0f*M_PI);
const float B = -16.0f;
const float C = 8.0f;
// scale angle for easy argument reduction
x *= A;
if (fabsf(x) >= 0.5f) {
// Argument reduction
x = x - ceilf(x + 0.5f) + 1.0f;
}
const float y = B*x*fabsf(x) + C*x;
return 0.2215f * (y*fabsf(y) - y) + y;
}
float cosinef(float x)
{
return sinef(x + float(M_PI/2));
}
void sincosf(GLfloat angle, GLfloat* s, GLfloat* c) {
*s = sinef(angle);
*c = cosinef(angle);
}
}; // namespace fp_utils
// ----------------------------------------------------------------------------
}; // namespace android