From 80785d7a7a231da3eb3707f90c83caddd2b3f92f Mon Sep 17 00:00:00 2001
From: Jean Privat <jean@pryen.org>
Date: Fri, 6 Jun 2014 21:50:13 -0400
Subject: [PATCH] lib/mnit: add tileset to manage tilesets and monospace
 bitmap fonts

Signed-off-by: Jean Privat <jean@pryen.org>
---
 lib/mnit/tileset.nit |  125 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 lib/mnit/tileset.nit

diff --git a/lib/mnit/tileset.nit b/lib/mnit/tileset.nit
new file mode 100644
index 0000000..7b473f3
--- /dev/null
+++ b/lib/mnit/tileset.nit
@@ -0,0 +1,125 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Manage images that are tileset or glyphset (for bitmap fonts)
+module tileset
+
+import mnit_display
+
+# Efficienly retrieve tiles in a big image
+class TileSet
+	# The image containing the tileset
+	var image: Image
+
+	# The witdh of a tile
+	var width: Int
+
+	# The height of a tile
+	var height: Int
+
+	init(image: Image, width: Int, height: Int)
+	do
+		self.image = image
+		self.width = width
+		self.height = height
+
+		self.nb_cols = image.width / width
+		self.nb_rows = image.height / height
+
+		for j in [0..nb_rows[ do
+			for i in [0..nb_cols[ do
+				subimages.add image.subimage(i*width,j*height,width,height)
+			end
+		end
+	end
+
+	# The number of columns of tiles in the image
+	var nb_cols: Int
+
+	# The number of rows of tiles in the image
+	var nb_rows: Int
+
+	# Cache for images of tiles
+	private var subimages = new Array[Image]
+
+	# The subimage of given tile
+	# Aborts if x or y are out of bound
+	fun [](x,y: Int): Image
+	do
+		assert x >= 0 and x < nb_cols and y >= 0 and y <= nb_rows else print "{x}x{y}<?{nb_cols}x{nb_rows}"
+		var idx = x + y * nb_cols
+		return subimages[idx]
+	end
+end
+
+# A monospace bitmap font where glyphs are stored in a tileset
+class TileSetFont
+	super TileSet
+
+	# Each caracter in the image
+	# in left->right, then top->bottom order
+	# Use space (' ') for holes in the tileset
+	var chars: String
+
+	init(image: Image, width: Int, height: Int, chars: String)
+	do
+		super
+		self.chars = chars
+	end
+
+	# Additional space to insert horizontally between characters
+	# A negave value will display tile overlaped
+	var hspace: Int writable = 0
+
+	# Additional space to insert vertically between characters
+	# A negave value will display tile overlaped
+	var vspace: Int writable = 0
+
+	# The glyph (tile) associated to the caracter `c` according to `chars`
+	# Returns null if `c` is not in `chars`
+	fun char(c: Char): nullable Image
+	do
+		var i = chars.index_of(c)
+		if i == -1 then return null
+		return subimages[i]
+	end
+end
+
+redef class Display
+	# Blit the text using a monospace bitmap font
+	# '\n' are rendered as carriage return
+	fun text(text: String, font: TileSetFont, x, y: Int)
+	do
+		var cx = x
+		var cy = y
+		var sw = font.width + font.hspace
+		var sh = font.height + font.vspace
+		for c in text.chars do
+			if c == '\n' then
+				cx = x
+				cy += sh
+				continue
+			end
+			if c == ' ' then
+				cx += sw
+				continue
+			end
+			var image = font.char(c)
+			if image != null then
+				blit(image, cx, cy)
+			end
+			cx += sw
+		end
+	end
+end
-- 
1.7.9.5