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Modify sin table

This commit is contained in:
Miloslav Číž 2018-11-20 17:34:10 +01:00
parent 513bc419b1
commit 4e1a808e1d

168
s3l.h
View file

@ -14,6 +14,8 @@
Angles are in S3L_Units, a full angle (2 pi) is S3L_FRACTIONS_PER_UNITs.
We use row vectors.
COORDINATE SYSTEMS:
In 3D space, a left-handed coord. system is used. One spatial unit is split
@ -58,20 +60,83 @@ typedef int16_t S3L_Unit; /**< Units of measurement in 3D space. There is
serves as 1.0 in floating point arithmetic
(normalization etc.). */
#define S3L_FRACTIONS_PER_UNIT 1024
#define S3L_FRACTIONS_PER_UNIT 512 /**< How many fractions a spatial unit is
split into. WARNING: if setting
higher than 1024, you'll probably
have to modify a sin table otherwise
it will overflow. Also other things
may overflow, so rather don't do it. */
#define S3L_SIN_TABLE_LENGTH 128
static const S3L_Unit S3L_sinTable[S3L_SIN_TABLE_LENGTH] =
{
0, 12, 25, 37, 50, 62, 75, 87, 100, 112, 125, 137, 150, 162, 175, 187, 199,
212, 224, 236, 248, 260, 273, 285, 297, 309, 321, 333, 344, 356, 368, 380,
391, 403, 414, 426, 437, 449, 460, 471, 482, 493, 504, 515, 526, 537, 547,
558, 568, 579, 589, 599, 609, 620, 629, 639, 649, 659, 668, 678, 687, 696,
706, 715, 724, 732, 741, 750, 758, 767, 775, 783, 791, 799, 807, 814, 822,
829, 837, 844, 851, 858, 865, 871, 878, 884, 890, 897, 903, 908, 914, 920,
925, 930, 936, 941, 946, 950, 955, 959, 964, 968, 972, 976, 979, 983, 986,
990, 993, 996, 999, 1001, 1004, 1006, 1008, 1010, 1012, 1014, 1016, 1017,
1019, 1020, 1021, 1022, 1022, 1023, 1023, 1023
/* 511 was chosen here as a highest number that doesn't overflow during
compilation for S3L_FRACTIONS_PER_UNIT == 1024 */
(0*S3L_FRACTIONS_PER_UNIT)/511, (6*S3L_FRACTIONS_PER_UNIT)/511,
(12*S3L_FRACTIONS_PER_UNIT)/511, (18*S3L_FRACTIONS_PER_UNIT)/511,
(25*S3L_FRACTIONS_PER_UNIT)/511, (31*S3L_FRACTIONS_PER_UNIT)/511,
(37*S3L_FRACTIONS_PER_UNIT)/511, (43*S3L_FRACTIONS_PER_UNIT)/511,
(50*S3L_FRACTIONS_PER_UNIT)/511, (56*S3L_FRACTIONS_PER_UNIT)/511,
(62*S3L_FRACTIONS_PER_UNIT)/511, (68*S3L_FRACTIONS_PER_UNIT)/511,
(74*S3L_FRACTIONS_PER_UNIT)/511, (81*S3L_FRACTIONS_PER_UNIT)/511,
(87*S3L_FRACTIONS_PER_UNIT)/511, (93*S3L_FRACTIONS_PER_UNIT)/511,
(99*S3L_FRACTIONS_PER_UNIT)/511, (105*S3L_FRACTIONS_PER_UNIT)/511,
(111*S3L_FRACTIONS_PER_UNIT)/511, (118*S3L_FRACTIONS_PER_UNIT)/511,
(124*S3L_FRACTIONS_PER_UNIT)/511, (130*S3L_FRACTIONS_PER_UNIT)/511,
(136*S3L_FRACTIONS_PER_UNIT)/511, (142*S3L_FRACTIONS_PER_UNIT)/511,
(148*S3L_FRACTIONS_PER_UNIT)/511, (154*S3L_FRACTIONS_PER_UNIT)/511,
(160*S3L_FRACTIONS_PER_UNIT)/511, (166*S3L_FRACTIONS_PER_UNIT)/511,
(172*S3L_FRACTIONS_PER_UNIT)/511, (178*S3L_FRACTIONS_PER_UNIT)/511,
(183*S3L_FRACTIONS_PER_UNIT)/511, (189*S3L_FRACTIONS_PER_UNIT)/511,
(195*S3L_FRACTIONS_PER_UNIT)/511, (201*S3L_FRACTIONS_PER_UNIT)/511,
(207*S3L_FRACTIONS_PER_UNIT)/511, (212*S3L_FRACTIONS_PER_UNIT)/511,
(218*S3L_FRACTIONS_PER_UNIT)/511, (224*S3L_FRACTIONS_PER_UNIT)/511,
(229*S3L_FRACTIONS_PER_UNIT)/511, (235*S3L_FRACTIONS_PER_UNIT)/511,
(240*S3L_FRACTIONS_PER_UNIT)/511, (246*S3L_FRACTIONS_PER_UNIT)/511,
(251*S3L_FRACTIONS_PER_UNIT)/511, (257*S3L_FRACTIONS_PER_UNIT)/511,
(262*S3L_FRACTIONS_PER_UNIT)/511, (268*S3L_FRACTIONS_PER_UNIT)/511,
(273*S3L_FRACTIONS_PER_UNIT)/511, (278*S3L_FRACTIONS_PER_UNIT)/511,
(283*S3L_FRACTIONS_PER_UNIT)/511, (289*S3L_FRACTIONS_PER_UNIT)/511,
(294*S3L_FRACTIONS_PER_UNIT)/511, (299*S3L_FRACTIONS_PER_UNIT)/511,
(304*S3L_FRACTIONS_PER_UNIT)/511, (309*S3L_FRACTIONS_PER_UNIT)/511,
(314*S3L_FRACTIONS_PER_UNIT)/511, (319*S3L_FRACTIONS_PER_UNIT)/511,
(324*S3L_FRACTIONS_PER_UNIT)/511, (328*S3L_FRACTIONS_PER_UNIT)/511,
(333*S3L_FRACTIONS_PER_UNIT)/511, (338*S3L_FRACTIONS_PER_UNIT)/511,
(343*S3L_FRACTIONS_PER_UNIT)/511, (347*S3L_FRACTIONS_PER_UNIT)/511,
(352*S3L_FRACTIONS_PER_UNIT)/511, (356*S3L_FRACTIONS_PER_UNIT)/511,
(361*S3L_FRACTIONS_PER_UNIT)/511, (365*S3L_FRACTIONS_PER_UNIT)/511,
(370*S3L_FRACTIONS_PER_UNIT)/511, (374*S3L_FRACTIONS_PER_UNIT)/511,
(378*S3L_FRACTIONS_PER_UNIT)/511, (382*S3L_FRACTIONS_PER_UNIT)/511,
(386*S3L_FRACTIONS_PER_UNIT)/511, (391*S3L_FRACTIONS_PER_UNIT)/511,
(395*S3L_FRACTIONS_PER_UNIT)/511, (398*S3L_FRACTIONS_PER_UNIT)/511,
(402*S3L_FRACTIONS_PER_UNIT)/511, (406*S3L_FRACTIONS_PER_UNIT)/511,
(410*S3L_FRACTIONS_PER_UNIT)/511, (414*S3L_FRACTIONS_PER_UNIT)/511,
(417*S3L_FRACTIONS_PER_UNIT)/511, (421*S3L_FRACTIONS_PER_UNIT)/511,
(424*S3L_FRACTIONS_PER_UNIT)/511, (428*S3L_FRACTIONS_PER_UNIT)/511,
(431*S3L_FRACTIONS_PER_UNIT)/511, (435*S3L_FRACTIONS_PER_UNIT)/511,
(438*S3L_FRACTIONS_PER_UNIT)/511, (441*S3L_FRACTIONS_PER_UNIT)/511,
(444*S3L_FRACTIONS_PER_UNIT)/511, (447*S3L_FRACTIONS_PER_UNIT)/511,
(450*S3L_FRACTIONS_PER_UNIT)/511, (453*S3L_FRACTIONS_PER_UNIT)/511,
(456*S3L_FRACTIONS_PER_UNIT)/511, (459*S3L_FRACTIONS_PER_UNIT)/511,
(461*S3L_FRACTIONS_PER_UNIT)/511, (464*S3L_FRACTIONS_PER_UNIT)/511,
(467*S3L_FRACTIONS_PER_UNIT)/511, (469*S3L_FRACTIONS_PER_UNIT)/511,
(472*S3L_FRACTIONS_PER_UNIT)/511, (474*S3L_FRACTIONS_PER_UNIT)/511,
(476*S3L_FRACTIONS_PER_UNIT)/511, (478*S3L_FRACTIONS_PER_UNIT)/511,
(481*S3L_FRACTIONS_PER_UNIT)/511, (483*S3L_FRACTIONS_PER_UNIT)/511,
(485*S3L_FRACTIONS_PER_UNIT)/511, (487*S3L_FRACTIONS_PER_UNIT)/511,
(488*S3L_FRACTIONS_PER_UNIT)/511, (490*S3L_FRACTIONS_PER_UNIT)/511,
(492*S3L_FRACTIONS_PER_UNIT)/511, (494*S3L_FRACTIONS_PER_UNIT)/511,
(495*S3L_FRACTIONS_PER_UNIT)/511, (497*S3L_FRACTIONS_PER_UNIT)/511,
(498*S3L_FRACTIONS_PER_UNIT)/511, (499*S3L_FRACTIONS_PER_UNIT)/511,
(501*S3L_FRACTIONS_PER_UNIT)/511, (502*S3L_FRACTIONS_PER_UNIT)/511,
(503*S3L_FRACTIONS_PER_UNIT)/511, (504*S3L_FRACTIONS_PER_UNIT)/511,
(505*S3L_FRACTIONS_PER_UNIT)/511, (506*S3L_FRACTIONS_PER_UNIT)/511,
(507*S3L_FRACTIONS_PER_UNIT)/511, (507*S3L_FRACTIONS_PER_UNIT)/511,
(508*S3L_FRACTIONS_PER_UNIT)/511, (509*S3L_FRACTIONS_PER_UNIT)/511,
(509*S3L_FRACTIONS_PER_UNIT)/511, (510*S3L_FRACTIONS_PER_UNIT)/511,
(510*S3L_FRACTIONS_PER_UNIT)/511, (510*S3L_FRACTIONS_PER_UNIT)/511,
(510*S3L_FRACTIONS_PER_UNIT)/511, (510*S3L_FRACTIONS_PER_UNIT)/511
};
#define S3L_SIN_TABLE_UNIT_STEP\
@ -80,32 +145,81 @@ static const S3L_Unit S3L_sinTable[S3L_SIN_TABLE_LENGTH] =
typedef int16_t S3L_ScreenCoord;
typedef uint16_t S3L_Index;
/**
Vector that consists of four scalars and can represent homogenous
coordinates, but is generally also used as Vec3 and Vec2.
*/
typedef struct
{
S3L_Unit x;
S3L_Unit y;
S3L_Unit z;
} S3L_Vec3;
S3L_Unit w;
} S3L_Vec4;
static inline void S3L_initVec3(S3L_Vec3 *v)
static inline void S3L_initVec4(S3L_Vec4 *v)
{
v->x = 0; v->y = 0; v->z = 0;
v->x = 0; v->y = 0; v->z = 0; v->w = S3L_FRACTIONS_PER_UNIT;
}
typedef S3L_Unit S3L_Mat4[3][3]; /**< 4x4 matrix, used mostly for 3D
transforms. The indexing is this:
matrix[column][row]. */
/**
Initializes a 4x4 matrix to identity.
*/
static inline void S3L_initMat4(S3L_Mat4 *m)
{
#define M(x,y) (*m)[x][y]
#define S S3L_FRACTIONS_PER_UNIT
M(0,0) = 0; M(1,0) = 0; M(2,0) = 0; M(3,0) = S;
M(0,1) = 0; M(1,1) = 0; M(2,1) = S; M(3,1) = 0;
M(0,2) = 0; M(1,2) = S; M(2,2) = 0; M(3,2) = 0;
M(0,3) = S; M(1,3) = 0; M(2,3) = 0; M(3,3) = 0;
#undef M
#undef S
}
/**
Multiplies a vector by a matrix.
*/
static inline void S3L_Vec4xMat4(S3L_Vec4 *v, S3L_Mat4 *m)
{
S3L_Vec4 vBackup;
vBackup.x = v->x;
vBackup.y = v->y;
vBackup.z = v->z;
vBackup.w = v->w;
v->x = vBackup.x * (*m)[0][0] +
vBackup.y * (*m)[0][1] +
vBackup.z * (*m)[0][2] +
vBackup.w * (*m)[0][3];
}
typedef struct
{
S3L_Vec3 offset;
S3L_Vec3 rotation; /**< Euler angles. Rortation is applied in this order:
S3L_Vec4 offset;
S3L_Vec4 rotation; /**< Euler angles. Rortation is applied in this order:
1. z = around z (roll) CW looking along z+
2. x = around x (pitch) CW looking along x+
3. y = around y (yaw) CW looking along y+ */
S3L_Vec3 scale;
S3L_Vec4 scale;
} S3L_Transform3D;
static inline void S3L_initTransoform3D(S3L_Transform3D *t)
{
S3L_initVec3(&(t->offset));
S3L_initVec3(&(t->rotation));
S3L_initVec4(&(t->offset));
S3L_initVec4(&(t->rotation));
t->scale.x = S3L_FRACTIONS_PER_UNIT;
t->scale.y = S3L_FRACTIONS_PER_UNIT;
t->scale.z = S3L_FRACTIONS_PER_UNIT;
@ -628,9 +742,12 @@ static inline void S3L_rotate2DPoint(S3L_Unit *x, S3L_Unit *y, S3L_Unit angle)
(angleCos * (*y)) / S3L_FRACTIONS_PER_UNIT;
}
// FIXME: rewrite this to just apply one matrix, EFFICIENCY!!!
static inline void S3L_mapModelToWorld(S3L_Vec3 point,
S3L_Transform3D *modelTransform, S3L_Vec3 *newPoint)
static inline void S3L_mapModelToWorld(S3L_Vec4 point,
S3L_Transform3D *modelTransform, S3L_Vec4 *newPoint)
{
newPoint->x = point.x;
newPoint->y = point.y;
@ -645,15 +762,18 @@ static inline void S3L_mapModelToWorld(S3L_Vec3 point,
newPoint->z += modelTransform->offset.z;
}
static inline void S3L_mapWorldToCamera(S3L_Vec3 point,
S3L_Transform3D *cameraTransform, S3L_Vec3 *newPoint)
static inline void S3L_mapWorldToCamera(S3L_Vec4 point,
S3L_Transform3D *cameraTransform, S3L_Vec4 *newPoint)
{
newPoint->x = point.x - cameraTransform->offset.x;
newPoint->y = point.y - cameraTransform->offset.y;
newPoint->z = point.z - cameraTransform->offset.z;
}
static inline void S3L_mapCameraToScreen(S3L_Vec3 point, S3L_Camera *camera,
static inline void S3L_mapCameraToScreen(S3L_Vec4 point, S3L_Camera *camera,
S3L_ScreenCoord *screenX, S3L_ScreenCoord *screenY)
{
uint16_t halfW = camera->resolutionX >> 1; // TODO: precompute earlier?
@ -676,7 +796,7 @@ void S3L_drawModel(
S3L_Index coordIndex = 0;
S3L_ScreenCoord sX0, sY0, sX1, sY1, sX2, sY2;
S3L_Vec3 pointModel, pointWorld, pointCamera;
S3L_Vec4 pointModel, pointWorld, pointCamera;
S3L_Unit indexIndex;
while (triangleIndex < triangleCount)