Add another example

2 files changed, 204 insertions, 2 deletions

diff --git a/examples/box_and_lines.c b/examples/box_and_lines.c
new file mode 100644
index 0000000..7026268
--- /dev/null
+++ b/examples/box_and_lines.c
@@ -0,0 +1,202 @@
+#include "cad.h"
+
+struct mid {
+	struct component p1;
+	struct component p2;
+
+	struct component lb;
+
+	struct component l1;
+	struct component l2;
+
+	struct component x1;
+
+	struct component p;
+
+	struct component m;
+};
+
+void a_midpoint(struct mid *mid, struct topology *topo, struct constraints *constr) {
+	*mid = (struct mid){
+		.p1 = {.type = COM_POINT},
+		.p2 = {.type = COM_POINT},
+		.lb = {.type = COM_LINE},
+
+		.l1 = {.type = COM_LINE},
+		.l2 = {.type = COM_LINE},
+
+		.x1 = {.type = COM_POINT},
+
+		.p = {.type = COM_LINE},
+
+		.m = {.type = COM_POINT},
+	};
+
+	if(constr != NULL) {
+		add_constraint(constr, (struct constraint[]){
+			POINT_ON_LINE(&mid->p1, &mid->lb),
+			POINT_ON_LINE(&mid->p2, &mid->lb),
+
+			LL_ANGLE(&mid->lb, &mid->l1, DEG(-30)),
+			POINT_ON_LINE(&mid->p1, &mid->l1),
+			LL_ANGLE(&mid->lb, &mid->l2, DEG(30)),
+			POINT_ON_LINE(&mid->p2, &mid->l2),
+
+			POINT_ON_LINE(&mid->x1, &mid->l1),
+			POINT_ON_LINE(&mid->x1, &mid->l2),
+
+			LL_ANGLE(&mid->lb, &mid->p, DEG(90)),
+			POINT_ON_LINE(&mid->x1, &mid->p),
+
+			POINT_ON_LINE(&mid->m, &mid->lb),
+			POINT_ON_LINE(&mid->m, &mid->p),
+
+			CEND(),
+		});
+	}
+}
+
+struct box {
+	struct component bottom_left;
+	struct component bottom_right;
+	struct component top_right;
+	struct component top_left;
+
+	struct component bottom;
+	struct component right;
+	struct component top;
+	struct component left;
+
+	struct mid left_mid;
+	struct mid right_mid;
+};
+
+void a_box(struct box *box, struct topology *topo, struct constraints *constr) {
+	assert(box != NULL);
+
+	*box = (struct box){
+		.bottom_left = {.type = COM_POINT},
+		.bottom_right = {.type = COM_POINT},
+		.top_right = {.type = COM_POINT},
+		.top_left = {.type = COM_POINT},
+
+		.bottom = {.type = COM_LINE},
+		.right = {.type = COM_LINE},
+		.top = {.type = COM_LINE},
+		.left = {.type = COM_LINE},
+	};
+
+	a_midpoint(&box->left_mid, topo, constr);
+	a_midpoint(&box->right_mid, topo, constr);
+
+	if(topo != NULL) {
+		add_fragment(topo, (struct topology_elem[]){
+			TOPO_MOVETO(&box->bottom_left),
+			TOPO_LINETO(&box->bottom_right),
+			TOPO_LINETO(&box->top_right),
+			TOPO_LINETO(&box->top_left),
+			TOPO_LINETO(&box->bottom_left),
+
+			TOPO_END(),
+		});
+	}
+
+	if(constr != NULL) {
+		add_constraint(constr, (struct constraint[]){
+			POINT_ON_LINE(&box->bottom_left, &box->bottom),
+			POINT_ON_LINE(&box->bottom_right, &box->bottom),
+
+			POINT_ON_LINE(&box->bottom_right, &box->right),
+			POINT_ON_LINE(&box->top_right, &box->right),
+
+			POINT_ON_LINE(&box->top_right, &box->top),
+			POINT_ON_LINE(&box->top_left, &box->top),
+
+			POINT_ON_LINE(&box->bottom_left, &box->left),
+			POINT_ON_LINE(&box->top_left, &box->left),
+
+			LL_ANGLE(&box->left, &box->bottom, DEG(90)),
+			LL_ANGLE(&box->right, &box->top, DEG(90)),
+			LL_ANGLE(&box->top, &box->left, DEG(90)),
+
+			PP_DISTANCE(&box->bottom_left, &box->bottom_right, 7),
+			PP_DISTANCE(&box->bottom_right, &box->top_right, 3),
+
+			// Bind the mids
+			PP_SAME(&box->left_mid.p1, &box->top_left),
+			PP_SAME(&box->left_mid.p2, &box->bottom_left),
+
+			PP_SAME(&box->right_mid.p1, &box->bottom_right),
+			PP_SAME(&box->right_mid.p2, &box->top_right),
+			CEND(),
+		});
+	}
+}
+
+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 box box1;
+	a_box(&box1, &topo, &constraints);
+
+	struct box box2;
+	a_box(&box2, &topo, &constraints);
+
+	struct box box3;
+	a_box(&box3, &topo, &constraints);
+
+	add_constraint(&constraints, (struct constraint[]){
+		POINT_ON_LINE(&box2.bottom_left, &box1.bottom),
+		PP_DISTANCE(&box1.bottom_right, &box2.bottom_left, 3),
+		LL_ANGLE(&box2.bottom, &box1.bottom, 0),
+
+		POINT_ON_LINE(&box3.bottom_left, &box1.bottom),
+		PP_DISTANCE(&box2.bottom_right, &box3.bottom_left, 3),
+		LL_ANGLE(&box3.bottom, &box2.bottom, 0),
+		CEND(),
+	});
+
+	add_fragment(&topo, (struct topology_elem[]){
+		TOPO_MOVETO(&box1.right_mid.m),
+		TOPO_LINETO(&box2.left_mid.m),
+
+		TOPO_MOVETO(&box2.right_mid.m),
+		TOPO_LINETO(&box3.left_mid.m),
+
+		TOPO_END(),
+	});
+
+	struct canvas canvas = {
+		.state = CANVAS_INIT,
+		.f = stdout,
+	};
+
+	draw_from_constraints(&constraints, &topo, &canvas);
+
+	free_constraints(&constraints);
+	free_topology(&topo);
+}
diff --git a/src/solve.c b/src/solve.c
index 630a0a6..8ea65c1 100644
--- a/src/solve.c
+++ b/src/solve.c
@@ -51,7 +51,7 @@ void free_constraints(struct constraints *c) {
 
 // @COMPL: We should do something better than this. I don't really know what.
 struct frontier {
-	struct component *elems[64];
+	struct component *elems[128];
 	size_t n;
 };
 
@@ -65,7 +65,7 @@ static bool frontier_scan(struct frontier *frontier, struct component *component
 
 static void add_frontier(struct frontier *frontier, struct component *component) {
 	assert(!frontier_scan(frontier, component));
-	assert(frontier->n < 64);
+	assert(frontier->n < 128);
 	frontier->elems[frontier->n++] = component;
 }