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/*-----------------------------------------------------------------------------
* Some sample code for slvs.dll. We draw some geometric entities, provide
* initial guesses for their positions, and then constrain them. The solver
* calculates their new positions, in order to satisfy the constraints.
*
* Copyright 2008-2013 Jonathan Westhues.
*---------------------------------------------------------------------------*/
#ifdef WIN32
# include <windows.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <slvs.h>
static Slvs_System sys;
static void *CheckMalloc(size_t n)
{
void *r = malloc(n);
if(!r) {
printf("out of memory!\n");
exit(-1);
}
return r;
}
/*-----------------------------------------------------------------------------
* An example of a constraint in 3d. We create a single group, with some
* entities and constraints.
*---------------------------------------------------------------------------*/
void Example3d()
{
/* This will contain a single group, which will arbitrarily number 1. */
Slvs_hGroup g = 1;
/* A point, initially at (x y z) = (10 10 10) */
sys.param[sys.params++] = Slvs_MakeParam(1, g, 10.0);
sys.param[sys.params++] = Slvs_MakeParam(2, g, 10.0);
sys.param[sys.params++] = Slvs_MakeParam(3, g, 10.0);
sys.entity[sys.entities++] = Slvs_MakePoint3d(101, g, 1, 2, 3);
/* and a second point at (20 20 20) */
sys.param[sys.params++] = Slvs_MakeParam(4, g, 20.0);
sys.param[sys.params++] = Slvs_MakeParam(5, g, 20.0);
sys.param[sys.params++] = Slvs_MakeParam(6, g, 20.0);
sys.entity[sys.entities++] = Slvs_MakePoint3d(102, g, 4, 5, 6);
/* and a line segment connecting them. */
sys.entity[sys.entities++] = Slvs_MakeLineSegment(200, g,
SLVS_FREE_IN_3D, 101, 102);
/* The distance between the points should be 30.0 units. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
1, g,
SLVS_C_PT_PT_DISTANCE,
SLVS_FREE_IN_3D,
30.0,
101, 102, 0, 0);
/* Let's tell the solver to keep the second point as close to constant
* as possible, instead moving the first point. */
sys.dragged[0] = 4;
sys.dragged[1] = 5;
sys.dragged[2] = 6;
/* Now that we have written our system, we solve. */
Slvs_Solve(&sys, g);
if(sys.result == SLVS_RESULT_OKAY) {
printf("okay; now at (%.3f %.3f %.3f)\n"
" (%.3f %.3f %.3f)\n",
sys.param[0].val, sys.param[1].val, sys.param[2].val,
sys.param[3].val, sys.param[4].val, sys.param[5].val);
printf("%d DOF\n", sys.dof);
} else {
printf("solve failed");
}
}
/*-----------------------------------------------------------------------------
* An example of a constraint in 2d. In our first group, we create a workplane
* along the reference frame's xy plane. In a second group, we create some
* entities in that group and dimension them.
*---------------------------------------------------------------------------*/
void Example2d()
{
Slvs_hGroup g;
double qw, qx, qy, qz;
g = 1;
/* First, we create our workplane. Its origin corresponds to the origin
* of our base frame (x y z) = (0 0 0) */
sys.param[sys.params++] = Slvs_MakeParam(1, g, 0.0);
sys.param[sys.params++] = Slvs_MakeParam(2, g, 0.0);
sys.param[sys.params++] = Slvs_MakeParam(3, g, 0.0);
sys.entity[sys.entities++] = Slvs_MakePoint3d(101, g, 1, 2, 3);
/* and it is parallel to the xy plane, so it has basis vectors (1 0 0)
* and (0 1 0). */
Slvs_MakeQuaternion(1, 0, 0,
0, 1, 0, &qw, &qx, &qy, &qz);
sys.param[sys.params++] = Slvs_MakeParam(4, g, qw);
sys.param[sys.params++] = Slvs_MakeParam(5, g, qx);
sys.param[sys.params++] = Slvs_MakeParam(6, g, qy);
sys.param[sys.params++] = Slvs_MakeParam(7, g, qz);
sys.entity[sys.entities++] = Slvs_MakeNormal3d(102, g, 4, 5, 6, 7);
sys.entity[sys.entities++] = Slvs_MakeWorkplane(200, g, 101, 102);
/* Now create a second group. We'll solve group 2, while leaving group 1
* constant; so the workplane that we've created will be locked down,
* and the solver can't move it. */
g = 2;
/* These points are represented by their coordinates (u v) within the
* workplane, so they need only two parameters each. */
sys.param[sys.params++] = Slvs_MakeParam(11, g, 10.0);
sys.param[sys.params++] = Slvs_MakeParam(12, g, 20.0);
sys.entity[sys.entities++] = Slvs_MakePoint2d(301, g, 200, 11, 12);
sys.param[sys.params++] = Slvs_MakeParam(13, g, 20.0);
sys.param[sys.params++] = Slvs_MakeParam(14, g, 10.0);
sys.entity[sys.entities++] = Slvs_MakePoint2d(302, g, 200, 13, 14);
/* And we create a line segment with those endpoints. */
sys.entity[sys.entities++] = Slvs_MakeLineSegment(400, g,
200, 301, 302);
/* Now three more points. */
sys.param[sys.params++] = Slvs_MakeParam(15, g, 100.0);
sys.param[sys.params++] = Slvs_MakeParam(16, g, 120.0);
sys.entity[sys.entities++] = Slvs_MakePoint2d(303, g, 200, 15, 16);
sys.param[sys.params++] = Slvs_MakeParam(17, g, 120.0);
sys.param[sys.params++] = Slvs_MakeParam(18, g, 110.0);
sys.entity[sys.entities++] = Slvs_MakePoint2d(304, g, 200, 17, 18);
sys.param[sys.params++] = Slvs_MakeParam(19, g, 115.0);
sys.param[sys.params++] = Slvs_MakeParam(20, g, 115.0);
sys.entity[sys.entities++] = Slvs_MakePoint2d(305, g, 200, 19, 20);
/* And arc, centered at point 303, starting at point 304, ending at
* point 305. */
sys.entity[sys.entities++] = Slvs_MakeArcOfCircle(401, g, 200, 102,
303, 304, 305);
/* Now one more point, and a distance */
sys.param[sys.params++] = Slvs_MakeParam(21, g, 200.0);
sys.param[sys.params++] = Slvs_MakeParam(22, g, 200.0);
sys.entity[sys.entities++] = Slvs_MakePoint2d(306, g, 200, 21, 22);
sys.param[sys.params++] = Slvs_MakeParam(23, g, 30.0);
sys.entity[sys.entities++] = Slvs_MakeDistance(307, g, 200, 23);
/* And a complete circle, centered at point 306 with radius equal to
* distance 307. The normal is 102, the same as our workplane. */
sys.entity[sys.entities++] = Slvs_MakeCircle(402, g, 200,
306, 102, 307);
/* The length of our line segment is 30.0 units. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
1, g,
SLVS_C_PT_PT_DISTANCE,
200,
30.0,
301, 302, 0, 0);
/* And the distance from our line segment to the origin is 10.0 units. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
2, g,
SLVS_C_PT_LINE_DISTANCE,
200,
10.0,
101, 0, 400, 0);
/* And the line segment is vertical. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
3, g,
SLVS_C_VERTICAL,
200,
0.0,
0, 0, 400, 0);
/* And the distance from one endpoint to the origin is 15.0 units. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
4, g,
SLVS_C_PT_PT_DISTANCE,
200,
15.0,
301, 101, 0, 0);
#if 0
/* And same for the other endpoint; so if you add this constraint then
* the sketch is overconstrained and will signal an error. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
5, g,
SLVS_C_PT_PT_DISTANCE,
200,
18.0,
302, 101, 0, 0);
#endif /* 0 */
/* The arc and the circle have equal radius. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
6, g,
SLVS_C_EQUAL_RADIUS,
200,
0.0,
0, 0, 401, 402);
/* The arc has radius 17.0 units. */
sys.constraint[sys.constraints++] = Slvs_MakeConstraint(
7, g,
SLVS_C_DIAMETER,
200,
17.0*2,
0, 0, 401, 0);
/* If the solver fails, then ask it to report which constraints caused
* the problem. */
sys.calculateFaileds = 1;
/* And solve. */
Slvs_Solve(&sys, g);
if(sys.result == SLVS_RESULT_OKAY) {
printf("solved okay\n");
printf("line from (%.3f %.3f) to (%.3f %.3f)\n",
sys.param[7].val, sys.param[8].val,
sys.param[9].val, sys.param[10].val);
printf("arc center (%.3f %.3f) start (%.3f %.3f) finish (%.3f %.3f)\n",
sys.param[11].val, sys.param[12].val,
sys.param[13].val, sys.param[14].val,
sys.param[15].val, sys.param[16].val);
printf("circle center (%.3f %.3f) radius %.3f\n",
sys.param[17].val, sys.param[18].val,
sys.param[19].val);
printf("%d DOF\n", sys.dof);
} else {
int i;
printf("solve failed: problematic constraints are:");
for(i = 0; i < sys.faileds; i++) {
printf(" %d", sys.failed[i]);
}
printf("\n");
if(sys.result == SLVS_RESULT_INCONSISTENT) {
printf("system inconsistent\n");
} else {
printf("system nonconvergent\n");
}
}
}
int main()
{
sys.param = CheckMalloc(50*sizeof(sys.param[0]));
sys.entity = CheckMalloc(50*sizeof(sys.entity[0]));
sys.constraint = CheckMalloc(50*sizeof(sys.constraint[0]));
sys.failed = CheckMalloc(50*sizeof(sys.failed[0]));
sys.faileds = 50;
/*Example3d();*/
for(;;) {
Example2d();
sys.params = sys.constraints = sys.entities = 0;
break;
}
return 0;
}
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