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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:23:22 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:23:22 +0000 |
commit | e42129241681dde7adae7d20697e7b421682fbb4 (patch) | |
tree | af1fe815a5e639e68e59fabd8395ec69458b3e5e /plug-ins/map-object/arcball.c | |
parent | Initial commit. (diff) | |
download | gimp-e42129241681dde7adae7d20697e7b421682fbb4.tar.xz gimp-e42129241681dde7adae7d20697e7b421682fbb4.zip |
Adding upstream version 2.10.22.upstream/2.10.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'plug-ins/map-object/arcball.c')
-rw-r--r-- | plug-ins/map-object/arcball.c | 515 |
1 files changed, 515 insertions, 0 deletions
diff --git a/plug-ins/map-object/arcball.c b/plug-ins/map-object/arcball.c new file mode 100644 index 0000000..1f509d4 --- /dev/null +++ b/plug-ins/map-object/arcball.c @@ -0,0 +1,515 @@ +/************************************/ +/* ArcBall.c (c) Ken Shoemake, 1993 */ +/* Modified by Tom Bech, 1996 */ +/************************************/ + +#include "config.h" + +#include <libgimp/gimp.h> + +#include "arcball.h" + +/* Global variables */ +/* ================ */ + +Quat qOne = { 0, 0, 0, 1 }; + +static HVect center; +static double radius; +static Quat qNow, qDown, qDrag; +static HVect vNow, vDown, vFrom, vTo, vrFrom, vrTo; +static HMatrix mNow, mDown; +static unsigned int showResult, dragging; +static ConstraintSet sets[NSets]; +static int setSizes[NSets]; +static AxisSet axisSet; +static int axisIndex; + +static HMatrix mId = +{ + { 1, 0, 0, 0 }, + { 0, 1, 0, 0 }, + { 0, 0, 1, 0 }, + { 0, 0, 0, 1 } +}; + +static double otherAxis[][4] = +{ + {-0.48, 0.80, 0.36, 1} +}; + +/* Internal methods */ +/* ================ */ + +static void Qt_ToMatrix(Quat q,HMatrix out); +static Quat Qt_Conj(Quat q); +static Quat Qt_Mul(Quat qL, Quat qR); +static Quat Qt_FromBallPoints(HVect from, HVect to); +static void Qt_ToBallPoints(Quat q, HVect *arcFrom, HVect *arcTo); + +static HVect V3_(double x, double y, double z); +static double V3_Norm(HVect v); +static HVect V3_Unit(HVect v); +static HVect V3_Scale(HVect v, double s); +static HVect V3_Negate(HVect v); +/* +static HVect V3_Add(HVect v1, HVect v2); +*/ +static HVect V3_Sub(HVect v1, HVect v2); +static double V3_Dot(HVect v1, HVect v2); +/* +static HVect V3_Cross(HVect v1, HVect v2); +static HVect V3_Bisect(HVect v0, HVect v1); +*/ + +static HVect MouseOnSphere(HVect mouse, HVect ballCenter, double ballRadius); +static HVect ConstrainToAxis(HVect loose, HVect axis); +static int NearestConstraintAxis(HVect loose, HVect *axes, int nAxes); + +/* Establish reasonable initial values for controller. */ +/* =================================================== */ + +void +ArcBall_Init (void) +{ + int i; + + center = qOne; + radius = 1.0; + vDown = vNow = qOne; + qDown = qNow = qOne; + for (i=15; i>=0; i--) + ((double *)mNow)[i] = ((double *)mDown)[i] = ((double *)mId)[i]; + + showResult = dragging = FALSE; + axisSet = NoAxes; + sets[CameraAxes] = mId[X]; + setSizes[CameraAxes] = 3; + sets[BodyAxes] = mDown[X]; + setSizes[BodyAxes] = 3; + sets[OtherAxes] = otherAxis[X]; + setSizes[OtherAxes] = 1; +} + +/* Set the center and size of the controller. */ +/* ========================================== */ + +void +ArcBall_Place (HVect Center, + double Radius) +{ + center = Center; + radius = Radius; +} + +/* Incorporate new mouse position. */ +/* =============================== */ + +void +ArcBall_Mouse (HVect v_Now) +{ + vNow = v_Now; +} + +/* Choose a constraint set, or none. */ +/* ================================= */ + +void +ArcBall_UseSet (AxisSet axis_Set) +{ + if (!dragging) axisSet = axis_Set; +} + +/* Using vDown, vNow, dragging, and axisSet, compute rotation etc. */ +/* =============================================================== */ + +void +ArcBall_Update (void) +{ + int setSize = setSizes[axisSet]; + HVect *set = (HVect *)(sets[axisSet]); + + vFrom = MouseOnSphere(vDown, center, radius); + vTo = MouseOnSphere(vNow, center, radius); + if (dragging) + { + if (axisSet!=NoAxes) + { + vFrom = ConstrainToAxis(vFrom, set[axisIndex]); + vTo = ConstrainToAxis(vTo, set[axisIndex]); + } + qDrag = Qt_FromBallPoints(vFrom, vTo); + qNow = Qt_Mul(qDrag, qDown); + } + else + { + if (axisSet!=NoAxes) axisIndex = NearestConstraintAxis(vTo, set, setSize); + } + Qt_ToBallPoints(qDown, &vrFrom, &vrTo); + Qt_ToMatrix(Qt_Conj(qNow), mNow); /* Gives transpose for GL. */ +} + +/* Return rotation matrix defined by controller use. */ +/* ================================================= */ + +void +ArcBall_Value (HMatrix m_Now) +{ + ArcBall_CopyMat (mNow, m_Now); +} + +/* Extract rotation angles from matrix */ +/* =================================== */ + +void +ArcBall_Values (double *alpha, + double *beta, + double *gamma) +{ + if ((*beta=asin(-mNow[0][2]))!=0.0) + { + *gamma=atan2(mNow[1][2],mNow[2][2]); + *alpha=atan2(mNow[0][1],mNow[0][0]); + } + else + { + *gamma=atan2(mNow[1][0],mNow[1][1]); + *alpha=0.0; + } +} + +/* Begin drag sequence. */ +/* ==================== */ + +void +ArcBall_BeginDrag (void) +{ + dragging = TRUE; + vDown = vNow; +} + +/* Stop drag sequence. */ +/* =================== */ + +void +ArcBall_EndDrag (void) +{ + dragging = FALSE; + qDown = qNow; + + ArcBall_CopyMat (mNow, mDown); +} + +/*===================*/ +/***** BallAux.c *****/ +/*===================*/ + +/* Return quaternion product qL * qR. Note: order is important! */ +/* To combine rotations, use the product Mul(qSecond, qFirst), */ +/* which gives the effect of rotating by qFirst then qSecond. */ +/* ============================================================= */ + +static Quat +Qt_Mul (Quat qL, + Quat qR) +{ + Quat qq; + qq.w = qL.w*qR.w - qL.x*qR.x - qL.y*qR.y - qL.z*qR.z; + qq.x = qL.w*qR.x + qL.x*qR.w + qL.y*qR.z - qL.z*qR.y; + qq.y = qL.w*qR.y + qL.y*qR.w + qL.z*qR.x - qL.x*qR.z; + qq.z = qL.w*qR.z + qL.z*qR.w + qL.x*qR.y - qL.y*qR.x; + return (qq); +} + +/* Construct rotation matrix from (possibly non-unit) quaternion. */ +/* Assumes matrix is used to multiply column vector on the left: */ +/* vnew = mat vold. Works correctly for right-handed coordinate */ +/* system and right-handed rotations. */ +/* ============================================================== */ + +static void +Qt_ToMatrix (Quat q, + HMatrix out) +{ + double Nq = q.x*q.x + q.y*q.y + q.z*q.z + q.w*q.w; + double s = (Nq > 0.0) ? (2.0 / Nq) : 0.0; + double xs = q.x*s, ys = q.y*s, zs = q.z*s; + double wx = q.w*xs, wy = q.w*ys, wz = q.w*zs; + double xx = q.x*xs, xy = q.x*ys, xz = q.x*zs; + double yy = q.y*ys, yz = q.y*zs, zz = q.z*zs; + out[X][X] = 1.0 - (yy + zz); out[Y][X] = xy + wz; out[Z][X] = xz - wy; + out[X][Y] = xy - wz; out[Y][Y] = 1.0 - (xx + zz); out[Z][Y] = yz + wx; + out[X][Z] = xz + wy; out[Y][Z] = yz - wx; out[Z][Z] = 1.0 - (xx + yy); + out[X][W] = out[Y][W] = out[Z][W] = out[W][X] = out[W][Y] = out[W][Z] = 0.0; + out[W][W] = 1.0; +} + +/* Return conjugate of quaternion. */ +/* =============================== */ + +static Quat +Qt_Conj (Quat q) +{ + Quat qq; + qq.x = -q.x; qq.y = -q.y; qq.z = -q.z; qq.w = q.w; + return (qq); +} + +/* Return vector formed from components */ +/* ==================================== */ + +static HVect +V3_ (double x, + double y, + double z) +{ + HVect v; + v.x = x; v.y = y; v.z = z; v.w = 0; + return (v); +} + +/* Return norm of v, defined as sum of squares of components */ +/* ========================================================= */ + +static double +V3_Norm (HVect v) +{ + return ( v.x*v.x + v.y*v.y + v.z*v.z ); +} + +/* Return unit magnitude vector in direction of v */ +/* ============================================== */ + +static HVect +V3_Unit (HVect v) +{ + static HVect u = {0, 0, 0, 0}; + double vlen = sqrt(V3_Norm(v)); + + if (vlen != 0.0) + { + u.x = v.x/vlen; + u.y = v.y/vlen; + u.z = v.z/vlen; + } + return (u); +} + +/* Return version of v scaled by s */ +/* =============================== */ + +static HVect +V3_Scale (HVect v, + double s) +{ + HVect u; + u.x = s*v.x; u.y = s*v.y; u.z = s*v.z; u.w = v.w; + return (u); +} + +/* Return negative of v */ +/* ==================== */ + +static HVect +V3_Negate (HVect v) +{ + static HVect u = {0, 0, 0, 0}; + u.x = -v.x; u.y = -v.y; u.z = -v.z; + return (u); +} + +/* Return sum of v1 and v2 */ +/* ======================= */ +/* +static HVect +V3_Add (HVect v1, + HVect v2) +{ + static HVect v = {0, 0, 0, 0}; + v.x = v1.x+v2.x; v.y = v1.y+v2.y; v.z = v1.z+v2.z; + return (v); +} +*/ +/* Return difference of v1 minus v2 */ +/* ================================ */ + +static HVect +V3_Sub (HVect v1, + HVect v2) +{ + static HVect v = {0, 0, 0, 0}; + v.x = v1.x-v2.x; v.y = v1.y-v2.y; v.z = v1.z-v2.z; + return (v); +} + +/* Halve arc between unit vectors v0 and v1. */ +/* ========================================= */ +/* +static HVect +V3_Bisect (HVect v0, + HVect v1) +{ + HVect v = {0, 0, 0, 0}; + double Nv; + + v = V3_Add(v0, v1); + Nv = V3_Norm(v); + if (Nv < 1.0e-5) v = V3_(0, 0, 1); + else v = V3_Scale(v, 1/sqrt(Nv)); + return (v); +} +*/ + +/* Return dot product of v1 and v2 */ +/* =============================== */ + +static double +V3_Dot (HVect v1, + HVect v2) +{ + return (v1.x*v2.x + v1.y*v2.y + v1.z*v2.z); +} + + +/* Return cross product, v1 x v2 */ +/* ============================= */ +/* +static HVect +V3_Cross (HVect v1, + HVect v2) +{ + static HVect v = {0, 0, 0, 0}; + v.x = v1.y*v2.z-v1.z*v2.y; + v.y = v1.z*v2.x-v1.x*v2.z; + v.z = v1.x*v2.y-v1.y*v2.x; + return (v); +} +*/ + +void +ArcBall_CopyMat (HMatrix inm, + HMatrix outm) +{ + int x=0,y=0; + + for (x=0;x<4;x++) + { + for (y=0;y<4;y++) + { + outm[y][x]=inm[y][x]; + } + } +} + +/*=====================================================*/ +/**** BallMath.c - Essential routines for ArcBall. ****/ +/*=====================================================*/ + +/* Convert window coordinates to sphere coordinates. */ +/* ================================================= */ + +static HVect +MouseOnSphere (HVect mouse, + HVect ballCenter, + double ballRadius) +{ + HVect ballMouse; + register double mag; + + ballMouse.x = (mouse.x - ballCenter.x) / ballRadius; + ballMouse.y = (mouse.y - ballCenter.y) / ballRadius; + mag = ballMouse.x*ballMouse.x + ballMouse.y*ballMouse.y; + if (mag > 1.0) + { + register double scale = 1.0/sqrt(mag); + ballMouse.x *= scale; ballMouse.y *= scale; + ballMouse.z = 0.0; + } + else ballMouse.z = sqrt(1 - mag); + ballMouse.w = 0.0; + return (ballMouse); +} + +/* Construct a unit quaternion from two points on unit sphere */ +/* ========================================================== */ + +static Quat +Qt_FromBallPoints (HVect from, + HVect to) +{ + Quat qu; + qu.x = from.y*to.z - from.z*to.y; + qu.y = from.z*to.x - from.x*to.z; + qu.z = from.x*to.y - from.y*to.x; + qu.w = from.x*to.x + from.y*to.y + from.z*to.z; + return (qu); +} + +/* Convert a unit quaternion to two points on unit sphere */ +/* ====================================================== */ + +static void +Qt_ToBallPoints (Quat q, + HVect *arcFrom, + HVect *arcTo) +{ + double s; + + s = sqrt(q.x*q.x + q.y*q.y); + if (s == 0.0) *arcFrom = V3_(0.0, 1.0, 0.0); + else *arcFrom = V3_(-q.y/s, q.x/s, 0.0); + arcTo->x = q.w*arcFrom->x - q.z*arcFrom->y; + arcTo->y = q.w*arcFrom->y + q.z*arcFrom->x; + arcTo->z = q.x*arcFrom->y - q.y*arcFrom->x; + if (q.w < 0.0) *arcFrom = V3_(-arcFrom->x, -arcFrom->y, 0.0); +} + +/* Force sphere point to be perpendicular to axis. */ +/* =============================================== */ + +static HVect +ConstrainToAxis (HVect loose, + HVect axis) +{ + HVect onPlane; + register double norm; + + onPlane = V3_Sub(loose, V3_Scale(axis, V3_Dot(axis, loose))); + norm = V3_Norm(onPlane); + if (norm > 0.0) + { + if (onPlane.z < 0.0) onPlane = V3_Negate(onPlane); + return ( V3_Scale(onPlane, 1/sqrt(norm)) ); + } + /* else drop through */ + /* ================= */ + + if (axis.z == 1) onPlane = V3_(1.0, 0.0, 0.0); + else onPlane = V3_Unit(V3_(-axis.y, axis.x, 0.0)); + return (onPlane); +} + +/* Find the index of nearest arc of axis set. */ +/* ========================================== */ + +static int +NearestConstraintAxis (HVect loose, + HVect *axes, + int nAxes) +{ + HVect onPlane; + register double max, dot; + register int i, nearest; + max = -1; nearest = 0; + + for (i=0; i<nAxes; i++) + { + onPlane = ConstrainToAxis(loose, axes[i]); + dot = V3_Dot(onPlane, loose); + if (dot>max) + { + max = dot; nearest = i; + } + } + return (nearest); +} |