Add a sprite draw function.

programs/basic_sprite.chalk

@@ -2,8 +2,11 @@ sprite dum [
 `  x  x  `
 `  x  x  `
 `  x  x  `
+`        `
+`x      x`
+` xxxxxx `
 ]
 
 fun main(): u0 {
-
+  draw_sprite(dum, 0, 0);
 }

src/chalk/compiler.cr

@@ -67,6 +67,7 @@ module Chalk
         table.set_function "get_delay", FunctionEntry.new Builtin::InlineGetDelayFunction.new
         table.set_function "set_sound", FunctionEntry.new Builtin::InlineSetSoundFunction.new
         table.set_function "draw_number", FunctionEntry.new Builtin::InlineDrawNumberFunction.new
+        table.set_function "draw_sprite", FunctionEntry.new Builtin::InlineDrawSpriteFunction.new
         return table
       end
 
@@ -180,15 +181,6 @@ module Chalk
         names = collect_calls(table)
         names.delete "main"
 
-        sprite_bytes = [] of UInt8
-        offset = 0
-        table.sprites.each do |k, v|
-          data = v.sprite.encode
-          v.offset = offset
-          offset += data.size
-          sprite_bytes.concat data
-        end
-
         main_entry = table.get_function?("main").not_nil!
         all_instructions.concat create_code(main_entry.function.as(Trees::TreeFunction),
           table, Ir::JumpRelativeInstruction.new 0)
@@ -203,9 +195,19 @@ module Chalk
           all_instructions << Ir::ReturnInstruction.new
         end
 
+        sprite_bytes = [] of UInt8
+        offset = 0
+        table.sprites.each do |k, v|
+          data = v.sprite.encode
+          v.addr = offset + all_instructions.size * 2
+          offset += data.size
+          sprite_bytes.concat data
+        end
+
         binary = [] of UInt8
         file = File.open(@config.output, "w")
         generate_binary(table, all_instructions, binary)
+        binary.concat sprite_bytes
         binary.each do |byte|
           file.write_byte byte
         end

src/chalk/inline.cr

@@ -81,5 +81,21 @@ module Chalk
           return Compiler::FunctionType.new([Compiler::Type::U8] * 3, Compiler::Type::U0)
       end
     end
+
+    class InlineDrawSpriteFunction < InlineFunction
+      def generate!(emitter, params, table, target, free)
+        raise "First parameter should be a sprite name." if !params[0].is_a?(Trees::TreeId)
+        sprite_name = params[0].as(Trees::TreeId).id
+        sprite = table.get_sprite?(sprite_name).not_nil!.sprite
+        emitter.generate! params[1], table, free, free + 1
+        emitter.generate! params[2], table, free + 1, free + 2
+        emitter.instructions << Ir::SetISpriteInstruction.new params[0].as(Trees::TreeId).id
+        emitter.instructions << Ir::DrawInstruction.new free, free + 1, sprite.height.to_i32
+      end
+
+      def type
+          return Compiler::FunctionType.new([Compiler::Type::U8] * 3, Compiler::Type::U0)
+      end
+    end
   end
 end

src/chalk/ir.cr

@@ -297,6 +297,21 @@ module Chalk
       end
     end
 
+    class SetISpriteInstruction < Instruction
+      getter name
+
+      def initialize(@name : String)
+      end
+
+      def to_s(io)
+        io << "setispr " << @name
+      end
+      
+      def to_bin(table, stack, index)
+        return 0xa000 | (table.get_sprite?(@name).not_nil!.addr + 0x200)
+      end
+    end
+
     # Instruction to add a register to I.
     class AddIRegInstruction < Instruction
       def initialize(@reg : Int32)

src/chalk/sprite.cr

@@ -5,6 +5,10 @@ module Chalk
         @pixels = Hash(UInt8, UInt8).new(default_value: 0_u8)
       end
 
+      def height
+        return (@pixels.keys.max || 0_u8) + 1
+      end
+
       def initialize(string, blank_char = ' ')
         @pixels = Hash(UInt8, UInt8).new(default_value: 0_u8)
         string.split("\n").each_with_index do |s, i|

src/chalk/table.cr

@@ -36,9 +36,9 @@ module Chalk
 
     class SpriteEntry
       property sprite : Sprite
-      property offset : Int32
+      property addr : Int32
 
-      def initialize(@sprite, @offset = -1)
+      def initialize(@sprite, @addr = -1)
       end
     end