★Trigonometric functions

function

slSin

Calculation of sine value

Format

    #include "sgl.h"

    ANGLE ang;
    FIXED slSin( ang )

argument

    ANGLE ang - Angle.

Return number

    FIXED - Sine value for the given angle.

function

Returns the sine of the specified angle. As a value The value will be between 0xffff0000 and 0x00010000.

Note

The angle data discards the lower 4 bits and is converted to 0x0000 to 0xfff0, so Accuracy is slightly lower (those using angles are subject to similar limitations).

reference

slCos	slTan	slAtan	slSquart
slSquartFX	slMulFX	slDivFX

function

slCos

Cosine value calculation

Format

    #include "sgl.h"

    ANGLE ang;    
    FIXED slCos( ang )

argument

    ANGLE ang - Angle.

Return number

    FIXED - Cosine value for the given angle.

function

Returns the cosine of the specified angle. As a value A value between 0xffff0000 and 0x00010000.

reference

slSin	slTan	slAtan	slSquart
slSquartFX	slMulFX	slDivFX

function

slTan

Calculation of tangent value

Format

    #include "sgl.h"

    ANGLE ang;
    FIXED slTan( ang )

argument

    ANGLE ang - Angle.

Return number

    FIXED - Tangent value for the given angle.

function

Returns the tangent of the specified angle.

Note

Accuracy cannot be expected because the tangent value is too large near 90 degrees.

reference

slSin	slCos	slAtan	slSquart
slSquartFX	slMulFX	slDivFX

function

slAtan

Calculating arctangent value

Format

    #include "sgl.h"

    FIXED x_pos, y_pos;
    ANGLE slAtan( x_pos, y_pos )

argument

    FIXED x_pos - X coordinate value
    FIXED y_pos - Y coordinate value

Return number

    FIXED - Arctangent value for the given vector.

function

Returns the angle in the specified direction.

reference

slSin	slCos	slTan	slSquart
slSquartFX	slMulFX	slDivFX

★Square root

function

slSquart

Square root operation

Format

    #include "sgl.h"

    Uint32 val;
    Uint16 slSquart( val )

argument

    Uint32 val - value.

Return number

    Uint16 The square root value of the given value, rounded down to the nearest whole number.

function

Calculates the square root of an unsigned integer.

reference

slSin	slCos	slTan	slAtan
slSquartFX	slMulFX	slDivFX

function

slSquartFX

Square root operation

Format

    #include "sgl.h"

    FIXED val;
    FIXED slSquartFX( val )

argument

    FIXED val - value.

Return number

    FIXED Square root value of the given value.

function

Calculates the square root of an unsigned fixed-point number.

Note

Since the calculation is performed as an integer, the precision of the result is an 8-bit integer and an 8-bit decimal.

reference

slSin	slCos	slTan	slAtan
slSquart	slMulFX	slDivFX

★Multiply and divide

function

slMulFX

Multiplying fixed decimal numbers

Format

    #include "sgl.h"

    FIXED val_a, val_b;
    FIXED slMulFX( val_a, val_b )

argument

    FIXED val_a, val_b - Fixed decimal values used for multiplication.

Return number

    FIXED - The result of multiplying the two numbers given as arguments.

function

Multiplies fixed decimal numbers and returns the result.

reference

slSin	slCos	slTan	slAtan
slSquart	slSquartFX	slDivFX

function

slDivFX

Fixed decimal division

Format

    #include "sgl.h"

    FIXED val_a, val_b;
    FIXED slDivFX( val_a, val_b )

argument

    FIXED val_a, val_b - Fixed decimal values used for division.

Return number

    FIXED - The result of dividing the two numbers given as arguments.

function

Divides fixed decimal numbers and returns the result (b/a).

reference

slSin	slCos	slTan	slAtan
slSquart	slSquartFX	slMulFX

★Vector calculation

function

slInnerProduct

Dot product calculation

Format

    #include "sgl.h"

    VECTOR vct_a, vct_b;
    FIXED slInnerProduct( vct_a, vct_b )

argument

    VECTOR vct_a, vct_b - Vector used for dot product operation.

Return number

    FIXED - The result of the dot product operation.

function

Takes the dot product of two vectors and returns the result.

example

    if( slInnerProduct ( normal, eye ) > toFIXED ( 0.0 ) ) {
      slPutPolygonX ( ... );
    }

reference

slNormal Vector

function

slNormal Vector

Find the normal vector of a plane containing 3 points

Format

    #include "sgl.h"

    VECTOR vct_a, vct_b, vct_c;
    VECTOR ans;

    void slNormalVector( vct_a, vct_b, vct_c, ans )

argument

    VECTOR vct_a, vct_b, vct_c - 3 points that make up the plane.

    VECTOR ans - VECTOR structure for storing calculation results.

Return number

    void - returns nothing. (However, the normal vector of the calculation result is returned to the ans argument.)

function

Calculates a vector (unit normal vector) orthogonal to two vectors (b->a, b->c) consisting of the specified three points.
If you want to reverse the direction of the normal, specify the points in the order of b , a , and c.

reference

slInnerProduct

★Random number

function

slRandom

find random number

Format

    #include "sgl.h"

    FIXED slRandom( void )

argument

    void - gives nothing.

Return number

    FIXED - Random value.

function

Generates a random number between 0 and 1.0.

example

    FIXED x, y;

    x = slMulFX ( slRandom (), toFIXED ( 320 ) );
    y = slMulFX ( slRandom (), toFIXED ( 240 ) );

Note

This function depends on the number of frames from slInitSystem .
In other words, the value of slRandom () immediately after starting slInitSystem will always be the same value. If you call this function immediately after starting slInitSystem , Please note that this has no meaning as a random number.

reference

slInitSystem

RandWork

★Motion/collision related

function

slBezier

Find the value of a Bezier curve connecting 4 points

Format

    #include "sgl.h"

    VECTOR pnt_a, pnt_b, pnt_c, pnt_d;
    VECTOR time;
    VECTOR ans; 

    void slBezier( pnt_a, pnt_b, pnt_c, pnt_d, time, ans )

argument

    VECTOR pnt_a, pnt_b, pnt_c, pnt_d - 4 points that make up the Bezier curve.

    VECTOR time - When pnt_a is 0.0 and pnt_d is 1.0,
                                        A point whose function value you want to know.

    VECTOR ans; - VECTOR structure for storing calculation results.

Return number

    void - returns nothing. (However, the vector of calculation results is returned to the ans argument.)

function

Returns the position in time of the Bezier curve connecting the specified four points.
Specify time in the range 0 to 1.0.

reference

function

slBallCollision

Determine collision between balls

Format

    #include "sgl.h"

    FIXED obj_a[ XYZ ];
    FIXED size_a;
    FIXED obj_b[ XYZ ];
    FIXED size_b;

    FIXED slBallCollision( obj_a, size_a, obj_b, size_b )

argument

    FIXED obj_a[ XYZ ] - Center coordinates of object A.

    FIXED size_a - radius of object A.

    FIXED obj_b[ XYZ ] - Center coordinates of object B.

    FIXED size_b - radius of object B.

Return number

    FIXED - If it is correct, returns the distance between the two, otherwise returns a negative number.

function

Checks whether the ball with position object [
If not, a negative value is returned.

example

    FIXED Orig[ XYZ ] = { toFIXED ( 0.0 ), toFIXED ( 0.0 ), toFIXED ( 0.0 ) }
    slPushMatrix ();
    {
           :
      slPushMatrix ();
      {
             :
        slConvert3Dto2DFX ( Orig, ans );
        if ( slBallCollision ( ans, radius1, obj, radius2 ) < toFIXED ( 0.0 ) ) {
                 Not Collide
             :
        } else {
                 Collide!!
        }

reference

★Slave

function

slSlaveFunc

Registration of functions to be executed by slave CPU

Format

    #include "sgl.h"

    void ( *func )() func;
    void *para;

    void slSlaveFunc( func, para );

argument

    void ( *func )() - the function you want to run on the slave.

    void *para - Arguments to give to the function executed on the slave.

Return number

    void - returns nothing.

function

Causes the slave CPU to execute the specified function.
If functions such as polygon display remain in the command buffer to the slave, the function will not be executed until they are finished, so the start of execution may be delayed.

example

    void foo() {
        :
    }
   
    slSlaveFunc ( foo, NULL );

reference