Add place for examples

and fix some bugs that make the examples not work!

4 files changed, 132 insertions, 5 deletions

diff --git a/Makefile b/Makefile
index 86f38e4..98e6346 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,7 @@ SRCDIR ?= src
 INCDIR ?= inc
 OBJDIR ?= obj
 TSTDIR ?= test
+EXMDIR ?= examples
 
 LIBS = -lm
 INCS = -Ithirdparty/cglm/include -Iinc/
@@ -24,7 +25,12 @@ TST_OBJS = $(TST_SOURCES:%.c=$(OBJDIR)/%.o)
 TST_DEPS = $(TST_OBJS:%.o=%.d)
 TST_APPS = $(TST_SOURCES:%.c=$(OBJDIR)/%)
 
--include $(APP_DEPS) $(APP_MAIN_DEPS) $(TST_DEPS)
+EXM_SOURCES = $(shell find $(EXMDIR) -name "*.c")
+EXM_OBJS = $(EXM_SOURCES:%.c=$(OBJDIR)/%.o)
+EXM_DEPS = $(EXM_OBJS:%.o=%.d)
+EXM_APPS = $(EXM_SOURCES:%.c=$(OBJDIR)/%)
+
+-include $(APP_DEPS) $(APP_MAIN_DEPS) $(TST_DEPS) $(EXM_DEPS)
 
 # We don't really need to run the tests for bear to record them
 compile_commands.json: clean Makefile $(APP_SOURCES)
@@ -42,6 +48,10 @@ $(OBJDIR)/test/%: $(OBJDIR)/test/%.o $(APP_OBJS)
 	@mkdir -p $(dir $@)
 	$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $< $(APP_OBJS) $(LIBS)
 
+$(OBJDIR)/examples/%: $(OBJDIR)/examples/%.o $(APP_OBJS)
+	@mkdir -p $(dir $@)
+	$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $< $(APP_OBJS) $(LIBS)
+
 clean:
 	@rm -rf $(OBJDIR)
 	@rm -f main
@@ -50,5 +60,7 @@ test: $(TST_APPS)
 	@echo "Running tests"
 	@for t in $(TST_APPS); do echo "$$t"; $$t; done
 
+examples: $(EXM_APPS)
+
 .DEFAULT_GOAL := all
-all: main test
+all: main test examples
diff --git a/examples/stacked.c b/examples/stacked.c
new file mode 100644
index 0000000..256a682
--- /dev/null
+++ b/examples/stacked.c
@@ -0,0 +1,115 @@
+#include "cad.h"
+
+struct box {
+	struct component corner[4];
+	struct component side[4];
+};
+
+void a_box(struct box *box, struct topology *topo, struct constraints *constr) {
+	assert(box != NULL);
+
+	*box = (struct box){
+		.corner = {
+			{.type = COM_POINT},
+			{.type = COM_POINT},
+			{.type = COM_POINT},
+			{.type = COM_POINT},
+		},
+		.side = {
+			{.type = COM_LINE},
+			{.type = COM_LINE},
+			{.type = COM_LINE},
+			{.type = COM_LINE},
+		},
+	};
+
+	if(topo != NULL) {
+		add_fragment(topo, (struct topology_elem[]){
+			TOPO_MOVETO(&box->corner[0]),
+			TOPO_LINETO(&box->corner[1]),
+			TOPO_LINETO(&box->corner[2]),
+			TOPO_LINETO(&box->corner[3]),
+			TOPO_LINETO(&box->corner[0]),
+
+			TOPO_END(),
+		});
+	}
+
+	if(constr != NULL) {
+		add_constraint(constr, (struct constraint[]){
+			POINT_ON_LINE(&box->corner[0], &box->side[0]),
+			POINT_ON_LINE(&box->corner[1], &box->side[0]),
+
+			POINT_ON_LINE(&box->corner[1], &box->side[1]),
+			POINT_ON_LINE(&box->corner[2], &box->side[1]),
+
+			POINT_ON_LINE(&box->corner[2], &box->side[2]),
+			POINT_ON_LINE(&box->corner[3], &box->side[2]),
+
+			POINT_ON_LINE(&box->corner[0], &box->side[3]),
+			POINT_ON_LINE(&box->corner[3], &box->side[3]),
+
+			LL_ANGLE(&box->side[3], &box->side[0], DEG(90)),
+			LL_ANGLE(&box->side[1], &box->side[2], DEG(90)),
+			LL_ANGLE(&box->side[2], &box->side[3], DEG(90)),
+			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);
+}
+
+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[]){
+		PP_DISTANCE(&box1.corner[0], &box1.corner[1], 10),
+		PP_DISTANCE(&box1.corner[1], &box1.corner[2], 10),
+
+		PP_SAME(&box2.corner[0], &box1.corner[3]),
+		PP_SAME(&box2.corner[1], &box1.corner[2]),
+		PP_DISTANCE(&box2.corner[1], &box2.corner[2], 10),
+
+		PP_SAME(&box3.corner[0], &box2.corner[3]),
+		PP_DISTANCE(&box3.corner[1], &box3.corner[2], 10),
+		PP_DISTANCE(&box3.corner[0], &box3.corner[1], 7),
+		LL_ANGLE(&box3.side[0], &box1.side[0], DEG(-40)),
+		CEND(),
+	});
+
+	struct canvas canvas = {
+		.state = CANVAS_INIT,
+		.f = stdout,
+	};
+	
+	draw_from_constraints(&constraints, &topo, &canvas);
+}
diff --git a/src/construction.c b/src/construction.c
index 23f02a7..090a36f 100644
--- a/src/construction.c
+++ b/src/construction.c
@@ -36,9 +36,9 @@ bool circle_line_intersect(struct circle circle, struct line line, uint8_t root,
 }
 
 void line_through_points(struct point p1, struct point p2, struct line* l) {
-	l->norm[0] = p1.pos[1] - p1.pos[1];
+	l->norm[0] = p1.pos[1] - p2.pos[1];
 	l->norm[1] = p2.pos[0] - p1.pos[0];
-	l->C = p1.pos[1] * -l->norm[1] + p1.pos[0] * -l->norm[1];
+	l->C = p1.pos[0] * -l->norm[0] + p1.pos[1] * -l->norm[1];
 }
 
 void line_line_intersect(struct line l1, struct line l2, struct point* p) {
diff --git a/src/solve.c b/src/solve.c
index 5cdff63..3f8e081 100644
--- a/src/solve.c
+++ b/src/solve.c
@@ -342,7 +342,7 @@ static void draw_solution(struct constraint *constraints, size_t fix, struct sol
 
 		struct element *distance = insert_cmd(drawing, (struct command){
 			.op = CMD_VALUE_INPUT,
-			.index = 0,
+			.index = fix,
 			.dir = constraints[fix].forward,
 			.result.type = ETYPE_VALUE,
 		});