Add an example for non-solvable figure

1 files changed, 90 insertions, 0 deletions

diff --git a/examples/triangle_tip.c b/examples/triangle_tip.c
new file mode 100644
index 0000000..408c864
--- /dev/null
+++ b/examples/triangle_tip.c
@@ -0,0 +1,90 @@
+#include "cad.h"
+
+void draw_from_constraints(struct constraints *c, struct topology *t, struct canvas *cv) {
+	struct drawing drawing = {};
+	bool rc = solve_constraints(c, &drawing);
+	assert(rc);
+
+	// Copy over all the parameter values to a new array
+	// @PERF: Maybe we should just store them in a separate array to start with
+	double *params = malloc(sizeof(double) * (c->length));
+	for(size_t i = 0; i < c->length; i++) {
+		params[i] = c->elements[i].v;
+	}
+
+	place_points(&drawing, params);
+	free(params);
+
+	begin_drawing(cv);
+	draw_topology(cv, t);
+	draw_constraints(cv, c);
+	end_drawing(cv);
+
+	free_drawing(&drawing);
+}
+
+int main(int argc, char *argv[]) {
+	struct constraints constraints = {};
+	struct topology topo = {};
+
+	struct component p1 = {.type = COM_POINT};
+	struct component p2 = {.type = COM_POINT};
+	struct component p3 = {.type = COM_POINT};
+
+	struct component p4 = {.type = COM_POINT};
+	struct component p5 = {.type = COM_POINT};
+
+	struct component t1base = {.type = COM_LINE};
+	struct component t2base = {.type = COM_LINE};
+	struct component t2side = {.type = COM_LINE};
+
+	add_constraint(&constraints, (struct constraint[]){
+		// Make a triangle
+		PP_DISTANCE(&p1, &p2, 30),
+		PP_DISTANCE(&p1, &p3, 30),
+		PP_DISTANCE(&p2, &p3, 30),
+
+		POINT_ON_LINE(&p1, &t1base),
+		POINT_ON_LINE(&p2, &t1base),
+
+		// With another triangle sharing a point
+		PP_DISTANCE(&p4, &p5, 30),
+		PP_DISTANCE(&p3, &p4, 30),
+
+		LL_ANGLE(&t2side, &t2base, DEG(120)),
+
+		POINT_ON_LINE(&p3, &t2side),
+		POINT_ON_LINE(&p4, &t2side),
+
+		POINT_ON_LINE(&p4, &t2base),
+		POINT_ON_LINE(&p5, &t2base),
+
+		// The edge they don't share is constrained
+		LL_ANGLE(&t1base, &t2base, DEG(80)),
+		CEND(),
+	});
+
+	add_fragment(&topo, (struct topology_elem[]){
+		TOPO_MOVETO(&p1),
+		TOPO_LINETO(&p2),
+		TOPO_LINETO(&p3),
+		TOPO_LINETO(&p1),
+
+		TOPO_MOVETO(&p3),
+		TOPO_LINETO(&p4),
+		TOPO_LINETO(&p5),
+		TOPO_LINETO(&p3),
+
+		TOPO_END(),
+	});
+
+	struct canvas canvas = {
+		.state = CANVAS_INIT,
+		.f = stdout,
+	};
+
+	draw_from_constraints(&constraints, &topo, &canvas);
+
+	free_constraints(&constraints);
+	return 0;
+}