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Add rotation matrix

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This commit is contained in:
Miloslav Číž 2018-11-21 18:00:05 +01:00
parent 8932e333b6
commit f542d31937
1 changed files with 115 additions and 60 deletions
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175
s3l.h
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@ -19,7 +19,7 @@
COORDINATE SYSTEMS:
In 3D space, a left-handed coord. system is used. One spatial unit is split
into S3L_FRACTIONS_PER_UNIT fractions.
into S3L_FRACTIONS_PER_UNIT fractions (fixed point arithmetic).
y ^
| _
@ -44,7 +44,7 @@
|
|
Coordinates of pixels on screen start typically at the top left.
Coordinates of pixels on screen start typically at the top left, from [0,0].
*/
#ifndef S3L_H
@ -222,6 +222,33 @@ void S3L_vec4Xmat4(S3L_Vec4 *v, S3L_Mat4 *m)
#undef dot
}
// general helper functions
static inline int16_t S3L_abs(int16_t value)
{
return value >= 0 ? value : -1 * value;
}
static inline int16_t S3L_min(int16_t v1, int16_t v2)
{
return v1 >= v2 ? v2 : v1;
}
static inline int16_t S3L_max(int16_t v1, int16_t v2)
{
return v1 >= v2 ? v1 : v2;
}
static inline S3L_Unit S3L_wrap(S3L_Unit value, S3L_Unit mod)
{
return value >= 0 ? (value % mod) : (mod + (value % mod) - 1);
}
static inline S3L_Unit S3L_nonZero(S3L_Unit value)
{
return value != 0 ? value : 1;
}
/**
Multiplies two matrices with normalization by S3L_FRACTIONS_PER_UNIT. Result
is stored in the first matrix.
@ -246,8 +273,36 @@ void S3L_mat4Xmat4(S3L_Mat4 *m1, S3L_Mat4 *m2)
}
}
static inline void S3L_makeTranslationMat(S3L_Unit offsetX, S3L_Unit offsetY,
S3L_Unit offsetZ, S3L_Mat4 *m)
S3L_Unit S3L_sin(S3L_Unit x)
{
x = S3L_wrap(x / S3L_SIN_TABLE_UNIT_STEP,S3L_SIN_TABLE_LENGTH * 4);
int8_t positive = 1;
if (x < S3L_SIN_TABLE_LENGTH)
x = x;
else if (x < S3L_SIN_TABLE_LENGTH * 2)
x = S3L_SIN_TABLE_LENGTH * 2 - x - 1;
else if (x < S3L_SIN_TABLE_LENGTH * 3)
{
x = x - S3L_SIN_TABLE_LENGTH * 2;
positive = 0;
}
else
{
x = S3L_SIN_TABLE_LENGTH - (x - S3L_SIN_TABLE_LENGTH * 3) - 1;
positive = 0;
}
return positive ? S3L_sinTable[x] : -1 * S3L_sinTable[x];
}
static inline S3L_Unit S3L_cos(S3L_Unit x)
{
return S3L_sin(x - S3L_FRACTIONS_PER_UNIT / 4);
}
void S3L_makeTranslationMat(
S3L_Unit offsetX, S3L_Unit offsetY, S3L_Unit offsetZ, S3L_Mat4 *m)
{
#define M(x,y) (*m)[x][y]
#define S S3L_FRACTIONS_PER_UNIT
@ -261,6 +316,48 @@ static inline void S3L_makeTranslationMat(S3L_Unit offsetX, S3L_Unit offsetY,
#undef S
}
/**
Makes a rotation matrix. For the rotation conventions (meaning, order, units)
see the appropriate structure comments.
*/
void S3L_makeRotationMatrix(
S3L_Unit aroundX, S3L_Unit aroundY, S3L_Unit aroundZ, S3L_Mat4 *m)
{
S3L_Unit sx = S3L_sin(aroundX);
S3L_Unit sy = S3L_sin(aroundY);
S3L_Unit sz = S3L_sin(aroundZ);
S3L_Unit cx = S3L_cos(aroundX);
S3L_Unit cy = S3L_cos(aroundY);
S3L_Unit cz = S3L_cos(aroundZ);
#define M(x,y) (*m)[x][y]
#define S S3L_FRACTIONS_PER_UNIT
M(0,0) = (cy * cz) / S + (sy * sx * sz) / (S * S);
M(1,0) = (cx * sz) / S;
M(2,0) = (cy * sx * sz) / (S * S) - (cz * sy) / S;
M(3,0) = 0;
M(0,1) = (cz * sy * sx) / (S * S) - (cy * sz) / S;
M(1,1) = (cx * cz) / S;
M(2,1) = (cy * cz * sx) / (S * S) + (sy * sz) / S;
M(3,1) = 0;
M(0,2) = (cx * sy) / S;
M(1,2) = -1 * sx;
M(2,2) = (cy * cx) / S;
M(3,2) = 0;
M(0,3) = 0;
M(1,3) = 0;
M(2,3) = 0;
M(3,3) = S3L_FRACTIONS_PER_UNIT;
#undef M
#undef S
}
typedef struct
{
S3L_Vec4 translation;
@ -369,61 +466,6 @@ static inline S3L_Unit S3L_interpolateBarycentric(
) / S3L_FRACTIONS_PER_UNIT;
}
// general helper functions
static inline int16_t S3L_abs(int16_t value)
{
return value >= 0 ? value : -1 * value;
}
static inline int16_t S3L_min(int16_t v1, int16_t v2)
{
return v1 >= v2 ? v2 : v1;
}
static inline int16_t S3L_max(int16_t v1, int16_t v2)
{
return v1 >= v2 ? v1 : v2;
}
static inline S3L_Unit S3L_wrap(S3L_Unit value, S3L_Unit mod)
{
return value >= 0 ? (value % mod) : (mod + (value % mod) - 1);
}
static inline S3L_Unit S3L_nonZero(S3L_Unit value)
{
return value != 0 ? value : 1;
}
static inline S3L_Unit S3L_sin(S3L_Unit x)
{
x = S3L_wrap(x / S3L_SIN_TABLE_UNIT_STEP,S3L_SIN_TABLE_LENGTH * 4);
int8_t positive = 1;
if (x < S3L_SIN_TABLE_LENGTH)
x = x;
else if (x < S3L_SIN_TABLE_LENGTH * 2)
x = S3L_SIN_TABLE_LENGTH * 2 - x - 1;
else if (x < S3L_SIN_TABLE_LENGTH * 3)
{
x = x - S3L_SIN_TABLE_LENGTH * 2;
positive = 0;
}
else
{
x = S3L_SIN_TABLE_LENGTH - (x - S3L_SIN_TABLE_LENGTH * 3) - 1;
positive = 0;
}
return positive ? S3L_sinTable[x] : -1 * S3L_sinTable[x];
}
static inline S3L_Unit S3L_cos(S3L_Unit x)
{
return S3L_sin(x - S3L_FRACTIONS_PER_UNIT / 4);
}
/**
Interpolated between two values, v1 and v2, in the same ratio as t is to
tMax. Does NOT prevent zero division.
@ -799,11 +841,24 @@ static inline void S3L_rotate2DPoint(S3L_Unit *x, S3L_Unit *y, S3L_Unit angle)
void S3L_makeWorldMatrix(S3L_Transform3D worldTransform, S3L_Mat4 *m)
{
S3L_makeRotationMatrix(
worldTransform.rotation.x,
worldTransform.rotation.y,
worldTransform.rotation.z,
m);
S3L_Mat4 t;
S3L_makeTranslationMat(
worldTransform.translation.x,
worldTransform.translation.y,
worldTransform.translation.z,
m);
&t);
S3L_mat4Xmat4(m,&t);
}
void S3L_makeCameraMatrix(S3L_Transform3D cameraTransform, S3L_Mat4 *m)