zoomedit: Implemented geometry functions.

Makefile.am

@@ -1,4 +1,4 @@
 bin_PROGRAMS  	     = zoomedit
-zoomedit_SOURCES     = zoomedit.c window.c ui.c draw.c level.c
+zoomedit_SOURCES     = zoomedit.c window.c ui.c draw.c level.c geometry.c
 zoomedit_CFLAGS      = @GTK_CFLAGS@
 zoomedit_LDADD       = @GTK_LIBS@

Makefile.in

@@ -50,7 +50,8 @@ binPROGRAMS_INSTALL = $(INSTALL_PROGRAM)
 PROGRAMS = $(bin_PROGRAMS)
 am_zoomedit_OBJECTS = zoomedit-zoomedit.$(OBJEXT) \
 	zoomedit-window.$(OBJEXT) zoomedit-ui.$(OBJEXT) \
-	zoomedit-draw.$(OBJEXT) zoomedit-level.$(OBJEXT)
+	zoomedit-draw.$(OBJEXT) zoomedit-level.$(OBJEXT) \
+	zoomedit-geometry.$(OBJEXT)
 zoomedit_OBJECTS = $(am_zoomedit_OBJECTS)
 zoomedit_DEPENDENCIES =
 zoomedit_LINK = $(CCLD) $(zoomedit_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) \
@@ -165,7 +166,7 @@ sysconfdir = @sysconfdir@
 target_alias = @target_alias@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
-zoomedit_SOURCES = zoomedit.c window.c ui.c draw.c level.c
+zoomedit_SOURCES = zoomedit.c window.c ui.c draw.c level.c geometry.c
 zoomedit_CFLAGS = @GTK_CFLAGS@
 zoomedit_LDADD = @GTK_LIBS@
 all: config.h
@@ -257,6 +258,7 @@ distclean-compile:
 	-rm -f *.tab.c
 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/zoomedit-draw.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/zoomedit-geometry.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/zoomedit-level.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/zoomedit-ui.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/zoomedit-window.Po@am__quote@
@@ -346,6 +348,20 @@ zoomedit-level.obj: level.c
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(zoomedit_CFLAGS) $(CFLAGS) -c -o zoomedit-level.obj `if test -f 'level.c'; then $(CYGPATH_W) 'level.c'; else $(CYGPATH_W) '$(srcdir)/level.c'; fi`
 
+zoomedit-geometry.o: geometry.c
+@am__fastdepCC_TRUE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(zoomedit_CFLAGS) $(CFLAGS) -MT zoomedit-geometry.o -MD -MP -MF $(DEPDIR)/zoomedit-geometry.Tpo -c -o zoomedit-geometry.o `test -f 'geometry.c' || echo '$(srcdir)/'`geometry.c
+@am__fastdepCC_TRUE@	mv -f $(DEPDIR)/zoomedit-geometry.Tpo $(DEPDIR)/zoomedit-geometry.Po
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='geometry.c' object='zoomedit-geometry.o' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(zoomedit_CFLAGS) $(CFLAGS) -c -o zoomedit-geometry.o `test -f 'geometry.c' || echo '$(srcdir)/'`geometry.c
+
+zoomedit-geometry.obj: geometry.c
+@am__fastdepCC_TRUE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(zoomedit_CFLAGS) $(CFLAGS) -MT zoomedit-geometry.obj -MD -MP -MF $(DEPDIR)/zoomedit-geometry.Tpo -c -o zoomedit-geometry.obj `if test -f 'geometry.c'; then $(CYGPATH_W) 'geometry.c'; else $(CYGPATH_W) '$(srcdir)/geometry.c'; fi`
+@am__fastdepCC_TRUE@	mv -f $(DEPDIR)/zoomedit-geometry.Tpo $(DEPDIR)/zoomedit-geometry.Po
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='geometry.c' object='zoomedit-geometry.obj' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(zoomedit_CFLAGS) $(CFLAGS) -c -o zoomedit-geometry.obj `if test -f 'geometry.c'; then $(CYGPATH_W) 'geometry.c'; else $(CYGPATH_W) '$(srcdir)/geometry.c'; fi`
+
 ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES)
 	list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \
 	unique=`for i in $$list; do \

draw.c

@@ -1,5 +1,6 @@
 #include "draw.h"
 #include "level.h"
+#include "geometry.h"
 #include <gtk/gtk.h>
 #include <cairo/cairo.h>
 
@@ -7,18 +8,31 @@
 static double scale = 100.0;
 static double xTranslate = 0.0, yTranslate = 0.0;
 
-static void room2path(cairo_t *cr, ROOM *room) {
+
+static void room2path(cairo_t *cr, ROOM *room, RECTANGLE *rect) {
   int i;
+  ROOM room2 = {0, NULL};
   
-  
+  // no vertices
   if(room->nVertices == 0) return;
   
-  cairo_move_to(cr, room->vertices[0].x, room->vertices[0].y);
+  if(rect)
+    simplifyPolygon(room, rect, &room2);
+  else
+    room2 = *room;
   
-  for(i = 1; i < room->nVertices; i++)
+  if(room2.nVertices == 0) return;
-    cairo_line_to(cr, room->vertices[i].x, room->vertices[i].y);
+  
+  cairo_new_sub_path(cr);
+  
+  for(i = 0; i < room2.nVertices; i++) {
+    cairo_line_to(cr, room2.vertices[i].x, room2.vertices[i].y);
+  }
   
   cairo_close_path(cr);
+  
+  if(rect && room2.vertices)
+    free(room2.vertices);
 }
 
 gboolean drawTopView(GtkWidget *widget, GdkEventExpose *event, gpointer data) {
@@ -26,21 +40,26 @@ gboolean drawTopView(GtkWidget *widget, GdkEventExpose *event, gpointer data) {
   ROOM room = {sizeof(vertices)/sizeof(vertices[0]), vertices};
   LEVEL lvl = {1, &room};
   cairo_t *cr;
+  RECTANGLE rect = {-5, -5, widget->allocation.width+10, widget->allocation.height+10};
   int i;
   
   
   cr = gdk_cairo_create(widget->window);
   
-  cairo_rectangle(cr, event->area.x, event->area.y, event->area.width, event->area.height);
+  gdk_cairo_region(cr, event->region);
   cairo_clip(cr);
   
   cairo_translate(cr, getImageWidth()/2-xTranslate, getImageHeight()/2-yTranslate);
   cairo_scale(cr, scale, scale);
   
+  cairo_device_to_user(cr, &rect.x, &rect.y);
+  cairo_device_to_user_distance(cr, &rect.width, &rect.height);
+  
   cairo_set_line_width(cr, 1.0/scale);
+  cairo_set_line_join(cr, CAIRO_LINE_JOIN_MITER);
   
   for(i = 0; i < lvl.nRooms; i++)
-    room2path(cr, &lvl.rooms[i]);
+    room2path(cr, &lvl.rooms[i], &rect);
   
   cairo_set_source_rgba(cr, 0.0, 0.7, 1.0, 0.3);
   cairo_fill_preserve(cr);

geometry.c

@@ -0,0 +1,218 @@
+#include "geometry.h"
+#include <math.h>
+#include <stdlib.h>
+#include <gtk/gtk.h>
+
+
+void addVertex(VERTEX_LIST *list, VERTEX *v) {
+  list->nVertices++;
+  list->vertices = realloc(list->vertices, list->nVertices*sizeof(VERTEX));
+  list->vertices[list->nVertices-1] = *v;
+}
+
+void insertVertex(VERTEX_LIST *list, VERTEX *v, unsigned int n) {
+  int i;
+  
+  if(n > list->nVertices)
+    n = list->nVertices;
+  
+  list->nVertices++;
+  list->vertices = realloc(list->vertices, list->nVertices*sizeof(VERTEX));
+  
+  for(i = list->nVertices-1; i > n; i--)
+    list->vertices[i] = list->vertices[i-1];
+  
+  list->vertices[n] = *v;
+}
+
+void deleteVertex(VERTEX_LIST *list, unsigned int n) {
+  int i;
+  
+  list->nVertices--;
+  
+  for(i = n; i < list->nVertices; i++)
+    list->vertices[i] = list->vertices[i+1];
+  
+  list->vertices = realloc(list->vertices, list->nVertices*sizeof(VERTEX));
+}
+
+double vertexDistanceSquare(const VERTEX *v1, const VERTEX *v2) {
+  return (v1->x-v2->x)*(v1->x-v2->x) + (v1->y-v2->y)*(v1->y-v2->y);
+}
+
+double vertexDistance(const VERTEX *v1, const VERTEX *v2) {
+  return sqrt(vertexDistanceSquare(v1, v2));
+}
+
+
+int vertexInRect(const VERTEX *v, const RECTANGLE *rect) {
+  int ret = EDGE_NONE;
+  
+  if(v->x < rect->x) ret |= EDGE_LEFT;
+  else if(v->x >= rect->x+rect->width) ret |= EDGE_RIGHT;
+  
+  if(v->y < rect->y) ret |= EDGE_TOP;
+  else if(v->y >= rect->y+rect->height) ret |= EDGE_BOTTOM;
+  
+  return ret;
+}
+
+int lineIntersection(const LINE *la, const LINE *lb, VERTEX *v) {
+  double xa1 = la->v1.x, ya1 = la->v1.y;
+  double xa2 = la->v2.x, ya2 = la->v2.y;
+  double xb1 = lb->v1.x, yb1 = lb->v1.y;
+  double xb2 = lb->v2.x, yb2 = lb->v2.y;
+  double temp;
+  int switched = 0;
+  
+  
+  if(xa1 == xa2 && ya1 == ya2) return INTERSECTION_ERROR;
+  if(xb1 == xb2 && yb1 == yb2) return INTERSECTION_ERROR;
+  
+  if(xa1 == xa2 || xb1 == xb2) {
+    temp = xa1; xa1 = ya1; ya1 = temp;
+    temp = xa2; xa2 = ya2; ya2 = temp;
+    temp = xb1; xb1 = yb1; yb1 = temp;
+    temp = xb2; xb2 = yb2; yb2 = temp;
+    
+    switched = 1;
+  }
+  
+  double ma = (ya2-ya1)/(xa2-xa1);
+  double mb = (yb2-yb1)/(xb2-xb1);
+  double ba = ya1 - ma*xa1;
+  double bb = yb1 - mb*xb1;
+  
+  if(ma == mb) return (ba == bb) ? INTERSECTION_IDENTICAL : INTERSECTION_NONE; 
+  
+  if(isinf(ma)) {
+    v->x = xa1;
+    v->y = yb1;
+  }
+  else if(isinf(mb)) {
+    v->x = xb1;
+    v->y = ya1;
+  }
+  else {
+    v->x = (bb-ba)/(ma-mb);
+    v->y = ma*v->x + ba;
+  }
+  
+  if(switched) {
+    temp = v->x; v->x = v->y; v->y = temp;
+    
+    //switch back everything for segment tests
+    temp = xa1; xa1 = ya1; ya1 = temp;
+    temp = xa2; xa2 = ya2; ya2 = temp;
+    temp = xb1; xb1 = yb1; yb1 = temp;
+    temp = xb2; xb2 = yb2; yb2 = temp;
+  }
+  
+  if(v->x < MIN(xa1,xa2) || v->x > MAX(xa1, xa2) || v->y < MIN(ya1,ya2) || v->y > MAX(ya1, ya2)) {
+    if(v->x < MIN(xb1,xb2) || v->x > MAX(xb1, xb2) || v->y < MIN(yb1,yb2) || v->y > MAX(yb1, yb2))
+      return INTERSECTION_LINE_LINE;
+    else
+      return INTERSECTION_LINE_SEGMENT;
+  }
+  else if(v->x < MIN(xb1,xb2) || v->x > MAX(xb1, xb2) || v->y < MIN(yb1,yb2) || v->y > MAX(yb1, yb2))
+    return INTERSECTION_SEGMENT_LINE;
+  else
+    return INTERSECTION_SEGMENT_SEGMENT;
+}
+
+int lineRectIntersection(const LINE *l, const RECTANGLE *rect, int edge, VERTEX *v) {
+  const double minX = rect->x, maxX = rect->x+rect->width;
+  const double minY = rect->y, maxY = rect->y+rect->height;
+  const LINE top = {{minX, minY}, {maxX, minY}};
+  const LINE bottom = {{minX, maxY}, {maxX, maxY}};
+  const LINE left = {{minX, minY}, {minX, maxY}};
+  const LINE right = {{maxX, minY}, {maxX, maxY}};
+  
+  if((edge & EDGE_TOP) && (lineIntersection(&top, l, v) == INTERSECTION_SEGMENT_SEGMENT))
+    return EDGE_TOP;
+  if((edge & EDGE_BOTTOM) && (lineIntersection(&bottom, l, v) == INTERSECTION_SEGMENT_SEGMENT))
+    return EDGE_BOTTOM;
+  if((edge & EDGE_LEFT) && (lineIntersection(&left, l, v) == INTERSECTION_SEGMENT_SEGMENT))
+    return EDGE_LEFT;
+  if((edge & EDGE_RIGHT) && (lineIntersection(&right, l, v) == INTERSECTION_SEGMENT_SEGMENT))
+    return EDGE_RIGHT;
+  
+  v->x = v->y = 0;
+  
+  return EDGE_NONE;
+}
+
+int lineRectIntersections(const LINE *line, const RECTANGLE *rect, int edge, VERTEX *v1, VERTEX *v2) {
+  int ret = EDGE_NONE;
+  
+  ret |= lineRectIntersection(line, rect, edge, v1);
+  ret |= lineRectIntersection(line, rect, EDGE_ALL^edge, v2);
+  
+  return ret;
+}
+
+void simplifyPolygon(const POLYGON *in, const RECTANGLE *rect, POLYGON *out) {
+  int i, j;
+  int a;
+  int lastVertex, thisVertex;
+  VERTEX v, v2;
+  VERTEX_LIST vl = {0, NULL};
+  LINE line;
+  LINE d1 = {{rect->x, rect->y}, {rect->x+rect->width, rect->y+rect->height}};
+  LINE d2 = {{rect->x, rect->y+rect->height}, {rect->x+rect->width, rect->y}};
+  
+  
+  thisVertex = vertexInRect(&in->vertices[0], rect);
+  
+  for(i = 0; i < in->nVertices; i++) {
+    line.v1 = in->vertices[i];
+    line.v2 = in->vertices[(i+1)%in->nVertices];
+    
+    lastVertex = thisVertex;
+    thisVertex = vertexInRect(&line.v2, rect);
+    
+    if(thisVertex == EDGE_NONE) {
+      if(lastVertex != EDGE_NONE && lineRectIntersection(&line, rect, lastVertex, &v))
+        addVertex(&vl, &v);
+      
+      addVertex(&vl, &line.v2);
+    }
+    else if(lastVertex == EDGE_NONE) {
+      if(lineRectIntersection(&line, rect, thisVertex, &v))
+        addVertex(&vl, &v);
+    }
+    else {
+      a = lineRectIntersections(&line, rect, lastVertex, &v, &v2);
+      
+      if((a & lastVertex) && (a & thisVertex)) {
+        addVertex(&vl, &v);
+        addVertex(&vl, &v2);
+      }
+      
+      if(lineIntersection(&line, &d1, &v) == INTERSECTION_SEGMENT_LINE) {
+        if(v.x <= rect->x) addVertex(&vl, &d1.v1);
+        else addVertex(&vl, &d1.v2);
+      }
+      
+      if(lineIntersection(&line, &d2, &v) == INTERSECTION_SEGMENT_LINE) {
+        if(v.x <= rect->x) addVertex(&vl, &d2.v1);
+        else addVertex(&vl, &d2.v2);
+      }
+    }
+    
+    while(vl.nVertices > 0) {
+      a = 0;
+      
+      for(j = 0; j < vl.nVertices; j++) {
+        if(vertexDistanceSquare(&line.v1, &vl.vertices[j]) < vertexDistanceSquare(&line.v1, &vl.vertices[a]))
+          a = j;
+      }
+      
+      if(out->nVertices == 0 || out->vertices[out->nVertices-1].x != vl.vertices[a].x ||
+         out->vertices[out->nVertices-1].y != vl.vertices[a].y)
+        addVertex(out, &vl.vertices[a]);
+      
+      deleteVertex(&vl, a);
+    }
+  }
+}

geometry.h

@@ -0,0 +1,50 @@
+#ifndef GEOMETRY_H_
+#define GEOMETRY_H_
+
+
+#define EDGE_NONE        0
+#define EDGE_LEFT   (1<<0)
+#define EDGE_RIGHT  (1<<1)
+#define EDGE_TOP    (1<<2)
+#define EDGE_BOTTOM (1<<3)
+#define EDGE_ALL    (EDGE_LEFT|EDGE_RIGHT|EDGE_TOP|EDGE_BOTTOM)
+
+#define INTERSECTION_ERROR          -1
+#define INTERSECTION_NONE            0
+#define INTERSECTION_IDENTICAL       1
+#define INTERSECTION_LINE_LINE       2
+#define INTERSECTION_LINE_SEGMENT    3
+#define INTERSECTION_SEGMENT_LINE    4
+#define INTERSECTION_SEGMENT_SEGMENT 5
+
+
+typedef struct _VERTEX {
+  double x, y;
+} VERTEX;
+
+typedef struct _RECTANGLE {
+  double x, y, width, height;
+} RECTANGLE;
+
+typedef struct _LINE {
+  VERTEX v1, v2;
+} LINE;
+
+typedef struct _VERTEX_LIST {
+  unsigned int nVertices;
+  VERTEX *vertices;
+} VERTEX_LIST, POLYGON;
+
+
+void addVertex(VERTEX_LIST *list, VERTEX *v);
+void insertVertex(VERTEX_LIST *list, VERTEX *v, unsigned int n);
+void deleteVertex(VERTEX_LIST *list, unsigned int n);
+
+
+int vertexInRect(const VERTEX *v, const RECTANGLE *rect);
+int lineIntersection(const LINE *la, const LINE *lb, VERTEX *v);
+int lineRectIntersection(const LINE *l, const RECTANGLE *rect, int edge, VERTEX *v);
+int lineRectIntersections(const LINE *line, const RECTANGLE *rect, int edge, VERTEX *v1, VERTEX *v2);
+void simplifyPolygon(const POLYGON *in, const RECTANGLE *rect, POLYGON *out);
+
+#endif /*GEOMETRY_H_*/

level.c

@@ -19,38 +19,6 @@ void deleteRoom(LEVEL *lvl, unsigned int n) {
   lvl->rooms = realloc(lvl->rooms, lvl->nRooms*sizeof(ROOM));
 }
 
-void addVertex(ROOM *room, VERTEX *v) {
-  room->nVertices++;
-  room->vertices = realloc(room->vertices, room->nVertices*sizeof(VERTEX));
-  room->vertices[room->nVertices-1] = *v;
-}
-
-void insertVertex(ROOM *room, VERTEX *v, unsigned int n) {
-  int i;
-  
-  if(n > room->nVertices)
-    n = room->nVertices;
-  
-  room->nVertices++;
-  room->vertices = realloc(room->vertices, room->nVertices*sizeof(VERTEX));
-  
-  for(i = room->nVertices-1; i > n; i--)
-    room->vertices[i] = room->vertices[i-1];
-  
-  room->vertices[n] = *v;
-}
-
-void deleteVertex(ROOM *room, unsigned int n) {
-  int i;
-  
-  room->nVertices--;
-  
-  for(i = n; i < room->nVertices; i++)
-    room->vertices[i] = room->vertices[i+1];
-  
-  room->vertices = realloc(room->vertices, room->nVertices*sizeof(VERTEX));
-}
-
 void freeLevel(LEVEL *lvl) {
   int i;
   

level.h

@@ -1,14 +1,9 @@
 #ifndef LEVEL_H_
 #define LEVEL_H_
 
-typedef struct _VERTEX {
+#include "geometry.h"
-  float x, y;
-} VERTEX;
 
-typedef struct _ROOM {
+typedef POLYGON ROOM;
-  unsigned int nVertices;
-  VERTEX *vertices;
-} ROOM;
 
 typedef struct _LEVEL {
   unsigned int nRooms;
@@ -18,10 +13,6 @@ typedef struct _LEVEL {
 void addRoom(LEVEL *lvl, ROOM *room);
 void deleteRoom(LEVEL *lvl, unsigned int n);
 
-void addVertex(ROOM *room, VERTEX *v);
-void insertVertex(ROOM *room, VERTEX *v, unsigned int n);
-void deleteVertex(ROOM *room, unsigned int n);
-
 void freeLevel(LEVEL *lvl);
 
 #endif /*LEVEL_H_*/