diff --git a/src/animation.c b/src/animation.c
index 54f90fb..cce244b 100644
--- a/src/animation.c
+++ b/src/animation.c
@@ -104,7 +104,7 @@ static unsigned int loadFrame(const char *path) {
 				int r0 = (int)floor(pr1 + HELI_PRECISION);
 				pr1 -= r0;
 				int r1 = r0 + 1;
-				if (r1 >= w) r1 = w - 1;
+				if (r1 >= h) r1 = h - 1;
 				if (r0 > r1) r0 = r1;
 				double pr0 = 1 - pr1;
 				
diff --git a/src/font.c b/src/font.c
index aced0b1..e04c0fa 100644
--- a/src/font.c
+++ b/src/font.c
@@ -96,20 +96,24 @@ static HeliFontMap* createFontMap() {
 	
 	glGenTextures(1, &map->texid);
 	glBindTexture(GL_TEXTURE_2D, map->texid);
+	
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
 	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_LOD_BIAS, -0.7f);
 	
-	char *buffer = calloc(1, FONT_MAP_TEXSIZE*FONT_MAP_TEXSIZE);
-	int level = 0;
-	for(int size = FONT_MAP_TEXSIZE, border = FONT_MAP_BORDERSIZE; border > 0; border >>= 1, size >>= 1, ++level)
+	unsigned char *buffer = (unsigned char*)calloc(1, FONT_MAP_TEXSIZE*FONT_MAP_TEXSIZE);
+	for(int level = 0, size = FONT_MAP_TEXSIZE; size > 0; ++level, size >>= 1)
 		glTexImage2D(GL_TEXTURE_2D, level, GL_ALPHA, size, size, 0, GL_ALPHA, GL_UNSIGNED_BYTE, buffer);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, level - 1);
 	free(buffer);
-	glBindTexture(GL_TEXTURE_2D, 0);
 	
+	int maxLevel = 0;
+	for(int border = FONT_MAP_BORDERSIZE; border > 0; border >>= 1) ++maxLevel;
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, maxLevel - 1);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, maxLevel - 1);
+	
+	glBindTexture(GL_TEXTURE_2D, 0);
 	return map;
 }
 
@@ -147,7 +151,7 @@ static HeliGlyph* loadGlyph(HeliFontInstance *fi, int code) {
 	g->b = (-metrics->horiBearingY + metrics->height)*ftkf;
 	g->advance = metrics->horiAdvance*ftkf;
 	
-	unsigned char buffer[FONT_MAP_GLYPHSIZE * FONT_MAP_GLYPHSIZE] = {};
+	unsigned char buffer[FONT_MAP_GLYPHSIZE*FONT_MAP_GLYPHSIZE] = {};
 	if (metrics->width > 0 && metrics->height > 0) {
 		FT_Matrix matrix = {};
 		matrix.xx = (FONT_MAP_GLYPHWORKSIZE-2)*64*65536/metrics->width;
@@ -157,7 +161,7 @@ static HeliGlyph* loadGlyph(HeliFontInstance *fi, int code) {
 		offset.y = -(64 + metrics->horiBearingY - metrics->height);
 		FT_Set_Transform(fi->face, &matrix, &offset);
 		int success = !FT_Load_Glyph(fi->face, index, FT_LOAD_NO_HINTING)
-				&& !FT_Render_Glyph(fi->face->glyph, FT_RENDER_MODE_NORMAL);
+		           && !FT_Render_Glyph(fi->face->glyph, FT_RENDER_MODE_NORMAL);
 		FT_Set_Transform(fi->face, NULL, NULL);
 		if (!success) return &blankGlyph;
 		
@@ -177,6 +181,8 @@ static HeliGlyph* loadGlyph(HeliFontInstance *fi, int code) {
 				buffer[r*FONT_MAP_GLYPHSIZE + c] = *(bitmap->buffer + bitmap->pitch*(r + dr) + c + dc);
 	}
 	
+	unsigned int prevtex = 0;
+	glGetIntegerv(GL_TEXTURE_BINDING_2D, (int*)&prevtex);
 	glBindTexture(GL_TEXTURE_2D, g->map->texid);
 	int gi = g - g->map->glyphs;
 	int r = gi/FONT_MAP_CNT;
@@ -204,7 +210,7 @@ static HeliGlyph* loadGlyph(HeliFontInstance *fi, int code) {
 					  + (unsigned int)buffer[((r*2 + 1)*size + c)*2 + 1] + 2) >> 2 );
 		}
 	}
-	glBindTexture(GL_TEXTURE_2D, 0);
+	glBindTexture(GL_TEXTURE_2D, prevtex);
 	
 	g->fi = fi;
 	g->code = code;
diff --git a/src/geometry.c b/src/geometry.c
index 6dc5391..eb2c291 100644
--- a/src/geometry.c
+++ b/src/geometry.c
@@ -109,8 +109,8 @@ double heliGLGetAAResolution() {
 	glGetIntegerv(GL_VIEWPORT, rect);
 	double w = rect[2], h = rect[3];
 	
-	double m00 = fullinv[0]*k*2/w, m01 = fullinv[2]*k/2*w,
-	       m10 = fullinv[4]*k*2/h, m11 = fullinv[5]*k/2*h;
+	double m00 = fullinv[0]*k*2/w, m01 = fullinv[1]*k*2/w,
+	       m10 = fullinv[4]*k*2/h, m11 = fullinv[5]*k*2/h;
 	double l0 = sqrt(m00*m00 + m01*m01);
 	double l1 = sqrt(m10*m10 + m11*m11);
 	if (l0 > l1) { double l = l0; l0 = l1; l1 = l; }
diff --git a/src/group.c b/src/group.c
index ca811be..f040286 100644
--- a/src/group.c
+++ b/src/group.c
@@ -55,7 +55,7 @@ void groupAdd(Group group, Sprite sprite) {
 	if (!sprite) return;
 	if (groupContains(group, sprite)) return;
 	heliArrayInsert(&group->sprites, -1, sprite, NULL);
-	heliArrayInsert(heliSpriteGetGroups(sprite), -1, sprite, NULL);
+	heliArrayInsert(heliSpriteGetGroups(sprite), -1, group, NULL);
 }
 
 void groupRemove(Group group, Sprite sprite) {
@@ -169,7 +169,7 @@ static void foreachString(Group group, const char *value, HeliSpriteEashString f
 
 
 void groupDestroyTimerEach(Group group, double lifetime)
-	{ foreachDouble(group, lifetime, &spriteDestroyTimer); }
+	{ for(int i = groupGetCount(group) - 1; i >= 0; --i) spriteDestroyTimer(groupGet(group, i), lifetime); }
 
 void groupSetVisibleEach(Group group, int visible)
 	{ foreachInt(group, visible, &spriteSetVisible); }
diff --git a/src/sprite.c b/src/sprite.c
index ecb437f..b36257e 100644
--- a/src/sprite.c
+++ b/src/sprite.c
@@ -126,12 +126,13 @@ void spriteDestroy(Sprite sprite) {
 	spriteSetNoAnimation(sprite);
 	while(sprite->groups.count > 0)
 		groupRemove((Group)sprite->groups.items[0].value, sprite);
-	for(int i = 0; i < sprites.count; ++i)
+	for(int i = sprites.count - 1; i >= 0; --i)
 		if (sprites.items[i].value == sprite)
-			{ heliArrayRemove(&sprites, i); break; }
-	for(int i = 0; i < spritesSorted.count; ++i)
+			heliArrayRemove(&sprites, i);
+	for(int i = spritesSorted.count - 1; i >= 0; --i)
 		if (spritesSorted.items[i].value == sprite)
-			{ heliArrayRemove(&spritesSorted, i); break; }
+			heliArrayRemove(&spritesSorted, i);
+	heliArrayDestroy(&sprite->groups);
 	heliObjectUnregister(sprite);
 	free(sprite);
 }
diff --git a/win/build-win.sh b/win/build-win.sh
index 350e12a..0501904 100755
--- a/win/build-win.sh
+++ b/win/build-win.sh
@@ -247,6 +247,8 @@ function build_demo() {
 	mkdir -p ../../release/demo
 	cp demo.exe ../../release/demo/demo$bits.exe
 	cp -r ../../../demo/data ../../release/demo/
+	mkdir -p ../../release/doc/
+	cp -r ../../../doc/ru ../../release/doc/
 }
 
 
diff --git a/win/rebuild-heli-win.sh b/win/rebuild-heli-win.sh
new file mode 100755
index 0000000..7031d64
--- /dev/null
+++ b/win/rebuild-heli-win.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+rm -f build*/helianthus.done build*/demo.done
+
+./build-win.sh