diff --git a/demo/src/phisics.c b/demo/src/phisics.c
index 2a90724..2aae432 100644
--- a/demo/src/phisics.c
+++ b/demo/src/phisics.c
@@ -13,24 +13,22 @@ static Sound beep;
 
 
 void phisicsInit() {
-	ball = createSpriteEx(200+1, 200+1, 64-2, 64-2);
-	spriteSetAnimation(ball, createAnimation("data/sprite/breadball.png"));
+	ball = createSpriteEx(200+1, 200+1, 64-2, 64-2, createAnimation("data/sprite/breadball.png"));
 	spriteSetColliderCircle(ball, 0, 0, -1);
 	spriteSetRotateToDirection(ball, TRUE);
 	
-	brick1 = createSpriteEx(200-32, 200+64, 64, 64);
-	spriteSetAnimation(brick1, createAnimation("data/sprite/bricks.png"));
+	brick1 = createSpriteEx(200-32, 200+64, 64, 64, createAnimation("data/sprite/bricks.png"));
 	spriteSetTintColor(brick1, colorByRGB(0, 0, 1));
 	spriteSetColliderRectangle(brick1, 0, 0, 0, -1, -1, 20);
 	spriteSetBounciness(brick1, 0.5);
 	spriteSetMassLevel(brick1, 1);
+	spriteSetDebug(brick1, TRUE);
 	
-	brick2 = createSpriteEx(200+32+1, 200+64+1, 64-2, 64-2);
-	spriteSetAnimation(brick2, createAnimation("data/sprite/bricks.png"));
+	brick2 = createSpriteEx(200+32+1, 200+64+1, 64-2, 64-2, createAnimation("data/sprite/bricks.png"));
 	spriteSetColliderRectangle(brick2, 0, 0, 0, -1, -1, 20);
+	spriteSetDebug(brick2, TRUE);
 	
-	brick3 = createSpriteEx(200+32+64, 200+64, 64, 64);
-	spriteSetAnimation(brick3, createAnimation("data/sprite/bricks.png"));
+	brick3 = createSpriteEx(200+32+64, 200+64, 64, 64, createAnimation("data/sprite/bricks.png"));
 	spriteSetTintColor(brick3, colorByRGBA(1, 0, 1, 0.5));
 	spriteSetColliderRectangle(brick3, 0, 0, 0, -1, -1, 20);
 	spriteSetBounciness(brick3, 2);
diff --git a/demo/src/sprites.c b/demo/src/sprites.c
index a2d0566..dbe2ce2 100644
--- a/demo/src/sprites.c
+++ b/demo/src/sprites.c
@@ -17,39 +17,34 @@ void spritesInit() {
 	double y = 16 + 48/2;
 	
 	// normal
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks.png"));
+	s = createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks.png"));
 	groupAdd(pulse, s);
 	x += 64;
 	
 	// indexed colors
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/snail-indexed.png"));
+	s = createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/snail-indexed.png"));
 	groupAdd(pulse, s);
 	x += 64;
 	
 	// without alpha
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
+	s = createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
 	groupAdd(pulse, s);
 	x += 64;
 	
 	// without texture
-	s = createSpriteEx(x, y, 48, 48);
+	s = createSprite(x, y, 48, 48);
 	spriteSetShapeColor(s, colorByName("blue"));
 	groupAdd(pulse, s);
 	x += 64;
 	
 	// with tint color
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks.png"));
+	s = createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks.png"));
 	spriteSetTintColor(s, colorByName("red"));
 	groupAdd(pulse, s);
 	x += 64;
 	
 	// semi-transparent
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks.png"));
+	s = createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks.png"));
 	spriteSetTintColor(s, colorByRGBA(1, 1, 1, 0.5));
 	groupAdd(pulse, s);
 	x += 64;
@@ -58,28 +53,21 @@ void spritesInit() {
 	y += 64;
 	
 	// tiles
-	s = createSpriteEx(x - 48/2, y + 48/2, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks.png"));
+	s = createSpriteEx(x - 48/2, y + 48/2, 48, 48, createAnimation("data/sprite/bricks.png"));
 	groupAdd(pulse, s);
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
-	s = createSpriteEx(x, y + 48, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
+	createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
+	createSpriteEx(x, y + 48, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
 	x -= 48;
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
-	s = createSpriteEx(x, y + 48, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
+	createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
+	createSpriteEx(x, y + 48, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
 	x -= 64;
 	
 	// blend two sprites
-	s = createSpriteEx(x, y, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
+	s = createSpriteEx(x, y, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
 	spriteSetTintColor(s, colorByRGBA(1, 1, 1, 0.5));
 	groupAdd(pulse, s);
 	x -= 16;
-	s = createSpriteEx(x, y + 16, 48, 48);
-	spriteSetAnimation(s, createAnimation("data/sprite/bricks-tile.png"));
+	s = createSpriteEx(x, y + 16, 48, 48, createAnimation("data/sprite/bricks-tile.png"));
 	spriteSetTintColor(s, colorByRGBA(1, 1, 1, 0.5));
 	groupAdd(pulse, s);
 	x -= 64;
@@ -87,8 +75,7 @@ void spritesInit() {
 	// texture size is not power of two
 	double k = 0.25, w = 343*k, h = 221*k;
 	x += 48/2 - w/2;
-	s = createSpriteEx(x, y, w, h);
-	spriteSetAnimation(s, createAnimation("data/sprite/snake.png"));
+	s = createSpriteEx(x, y, w, h, createAnimation("data/sprite/snake.png"));
 	spriteSetDebug(s, TRUE);
 	groupAdd(pulse, s);
 }
diff --git a/doc/helianthus-doc-ru.odt b/doc/helianthus-doc-ru.odt
index a66c167..eda0ced 100644
Binary files a/doc/helianthus-doc-ru.odt and b/doc/helianthus-doc-ru.odt differ
diff --git a/src/group.c b/src/group.c
index 089ea07..4d22671 100644
--- a/src/group.c
+++ b/src/group.c
@@ -29,10 +29,10 @@ Group createEdgesGroupEx(double x1, double y1, double x2, double y2, double bord
 	y1 -= b;
 	
 	Group g = createGroup();
-	groupAdd(g, createSpriteEx(x1 + w/2, y1 + b/2, w, b));
-	groupAdd(g, createSpriteEx(x1 + w/2, y2 + b/2, w, b));
-	groupAdd(g, createSpriteEx(x1 + b/2, y1 + h/2, b, h));
-	groupAdd(g, createSpriteEx(x2 + b/2, y1 + h/2, b, h));
+	groupAdd(g, createSprite(x1 + w/2, y1 + b/2, w, b));
+	groupAdd(g, createSprite(x1 + w/2, y2 + b/2, w, b));
+	groupAdd(g, createSprite(x1 + b/2, y1 + h/2, b, h));
+	groupAdd(g, createSprite(x2 + b/2, y1 + h/2, b, h));
 	groupSetMassLevelEach(g, massLevel);
 	return g;
 }
diff --git a/src/sprite.c b/src/sprite.c
index da8ab78..bb3cceb 100644
--- a/src/sprite.c
+++ b/src/sprite.c
@@ -89,10 +89,15 @@ static void prepareCollider(Sprite sprite, HeliCollider *collider) {
 	if (collider->type == COLLIDER_RECTANGLE) {
 		double rmax = 0.5*( collider->width < collider->height
 						  ? collider->width : collider->height );
-		if (collider->radius >= rmax - HELI_PRECISION)
+		if (collider->radius >= rmax - HELI_PRECISION) {
 			collider->radius = rmax;
-		collider->width  -= 2*collider->radius;
-		collider->height -= 2*collider->radius;
+			collider->type = COLLIDER_CIRCLE;
+			collider->width = 0;
+			collider->height = 0;
+		} else {
+			collider->width  -= 2*collider->radius;
+			collider->height -= 2*collider->radius;
+		}
 	}
 }
 
@@ -103,7 +108,7 @@ static void autoRotate(Sprite sprite) {
 }
 
 
-Sprite createSpriteEx(double x, double y, double width, double height) {
+Sprite createSpriteEx(double x, double y, double width, double height, Animation animation) {
 	if (!heliInitialized) return NULL;
 
 	Sprite s = calloc(1, sizeof(*s));
@@ -111,6 +116,7 @@ Sprite createSpriteEx(double x, double y, double width, double height) {
 	s->y = y;
 	s->width = width;
 	s->height = height;
+	s->animation = animation;
 	
 	s->scale = 1;
 	s->collider.type = COLLIDER_RECTANGLE;
@@ -137,8 +143,8 @@ Sprite createSpriteEx(double x, double y, double width, double height) {
 	return s;
 }
 
-Sprite createSprite(double x, double y)
-	{ return createSpriteEx(x, y, 100, 100); }
+Sprite createSprite(double x, double y, double width, double height)
+	{ return createSpriteEx(x, y, width, height, NULL); }
 
 void spriteDestroy(Sprite sprite) {
 	if (sprite->destroyCallback) sprite->destroyCallback(sprite);
@@ -528,6 +534,20 @@ void heliSpriteDrawDebug(Sprite s) {
 	line(-hw/4, 0, hw/4, 0);
 	line(0, -hh/4, 0, hh/4);
 	
+	// collider
+	HeliCollider cl = {};
+	prepareCollider(s, &cl);
+	saveState();
+	rotate(-s->rotation);
+	translate(-s->x, -s->y);
+	translate(cl.x, cl.y);
+	rotate(cl.rotation);
+	stroke(colorByRGBA(0, 0, 1, 0.75));
+	double cw = cl.width + 2*cl.radius;
+	double ch = cl.height + 2*cl.radius;
+	rectRounded(-cw/2, -ch/2, cw, ch, cl.radius);
+	restoreState();
+	
 	// depth
 	double s1 = hw*0.25;
 	double s2 = hh*0.5;
diff --git a/src/sprite.h b/src/sprite.h
index 7694f8a..d45f011 100644
--- a/src/sprite.h
+++ b/src/sprite.h
@@ -16,8 +16,8 @@ typedef enum _Collider {
 } Collider;
 
 
-Sprite createSprite(double x, double y);
-Sprite createSpriteEx(double x, double y, double width, double height);
+Sprite createSprite(double x, double y, double width, double height);
+Sprite createSpriteEx(double x, double y, double width, double height, Animation animation);
 
 void spriteDestroy(Sprite sprite);
 void spriteDestroyTimer(Sprite sprite, double lifetime);