This file is for fast functions for fixed point numbers like trigonometric functions, square root, etc.
| sparrowMath | This file is for fast functions for fixed point numbers like trigonometric functions, square root, etc. |
| Functions | |
| spInitMath | Initializes the fixed point look up tables for sin, cos, etc. |
| spSin | Calculates the sinus of a fixed point value |
| spCos | Calculates the cosinus of a fixed point value |
| spTan | Calculates the tangent of a fixed point value |
| spAsin | Calculates the arcus sinus of a fixed point value |
| spAcos | Calculates the arcus cosinus of a fixed point value |
| spSqrt | Fast square root for fixed point numbers |
| spUnsave_Small_Sqrt | This functions returns the square root of a number between 0 and 1 << SP_SQRT_ACCURACY. |
| spMin | Returns the smallest of 2 numbers. |
| spMax | Returns the biggest of 2 numbers. |
| spAtof | Converts a string to a Sint32 fixed point number like atof. |
| spSetRand | Does in fact the same as srand() of the glibc or other implementations. |
| spRand | Returns a pseudo random number. |
PREFIX void spInitMath( void )
Initializes the fixed point look up tables for sin, cos, etc. Is called by spInitCore.
PREFIX Sint32 spUnsave_Small_Sqrt( Sint32 n )
This functions returns the square root of a number between 0 and 1 << SP_SQRT_ACCURACY. If you give a number outside this range IT WILL CRASH! So use spSqrt if you are unsure. The light calculation uses this function for fast rendering.
| n | as said a fixed point value between 0 and 1 << SP_SQRT_ACCURACY |
| Sint32 | the square root of n. Always keep in mind, that the normal fixed point numbers with shift of SP_ACCURACY may not be compatible to this fixed point numbers with shift of SP_SQRT_ACCURACY! |
PREFIX Sint32 spMin( Sint32 a, Sint32 b )
Returns the smallest of 2 numbers. To get the smallest of three and more numbers, use a tree like function call like: spMin(spMin(a,b),c) or spMin(spMin(a,b),spMin(c,d)).
| a,b | numbers to compare |
| Sint32 | the smaller number. If the numbers are even, it returns the bigger on. |
PREFIX Sint32 spMax( Sint32 a, Sint32 b )
Returns the biggest of 2 numbers. To get the biggest of three and more numbers, use a tree like function call like: spMax(spMax(a,b),c) or spMax(spMax(a,b),spMax(c,d)).
| a,b | numbers to compare |
| Sint32 | the bigger number. If the numbers are even, it returns the smaller on. |
PREFIX Sint32 spAtof( char * buffer )
Converts a string to a Sint32 fixed point number like atof. Be careful, it is slow, especially on devices without FPU. But perfect for loading stuff.
| buffer | string to convert |
| Sint32 | the fixed point value stored in buffer. That means, if buffer is “12.3” the fixed point conversion of 12.3 will be saved, which is 806092 and not 12. ;) |
PREFIX void spSetRand( Sint32 seed )
Does in fact the same as srand() of the glibc or other implementations. It sets the start value of the random function. However this implementation is deterministic the same on every target, doesn’t matter whether Windows, Linux or a Toaster.
| seed | seed of the Randomness. Default is 0. |
Initializes the fixed point look up tables for sin, cos, etc.
PREFIX void spInitMath( void )
Calculates the sinus of a fixed point value
PREFIX Sint32 spSin( Sint32 value )
Calculates the cosinus of a fixed point value
PREFIX Sint32 spCos( Sint32 value )
Calculates the tangent of a fixed point value
PREFIX Sint32 spTan( Sint32 value )
Calculates the arcus sinus of a fixed point value
PREFIX Sint32 spAsin( Sint32 value )
Calculates the arcus cosinus of a fixed point value
PREFIX Sint32 spAcos( Sint32 value )
Fast square root for fixed point numbers
PREFIX Sint32 spSqrt ( Sint32 n )
This functions returns the square root of a number between 0 and 1 << SP_SQRT_ACCURACY.
PREFIX Sint32 spUnsave_Small_Sqrt( Sint32 n )
Returns the smallest of 2 numbers.
PREFIX Sint32 spMin( Sint32 a, Sint32 b )
Returns the biggest of 2 numbers.
PREFIX Sint32 spMax( Sint32 a, Sint32 b )
Converts a string to a Sint32 fixed point number like atof.
PREFIX Sint32 spAtof( char * buffer )
Does in fact the same as srand() of the glibc or other implementations.
PREFIX void spSetRand( Sint32 seed )
Returns a pseudo random number.
PREFIX Sint32 spRand( void )
spInitCore initializes SDL, SDL_TTF and other stuff.
PREFIX void spInitCore( void )