gamnit: add customization settings to `TextSprites`

[nit.git] / lib / gamnit / font.nit

diff --git a/lib/gamnit/font.nit b/lib/gamnit/font.nit
index 8a5defe..df46590 100644 (file)
--- a/lib/gamnit/font.nit
+++ b/lib/gamnit/font.nit
@@ -36,7 +36,17 @@ class TextSprites
        # Font used to draw text
        var font: Font
 
-       # Top left of the first character in UI coordinates
+       # Reference coordinates of this block of text
+       #
+       # When left aligned, the default at `align == 0.0`, the anchor is the
+       # left coordinate of the first character of the first line.
+       # When right aligned, at `align == 1.0`, the anchor is the right
+       # coordinate of the last character.
+       # When centered, at `align == 0.5`, the anchor is at the center.
+       #
+       # When top aligned, the default at `valign == 0.0`, the anchor is at the
+       # top of this block of text.
+       # When bottom aligned, at `valign == 1.0`, the anchor is at the bottom.
        var anchor: Point3d[Float]
 
        # Last set of sprites generated to display `text=`
@@ -48,7 +58,9 @@ class TextSprites
        # `app::sprites` or a custom collection.
        var target_sprite_set: Set[Sprite] = app.ui_sprites is lazy, writable
 
-       private var cached_text: nullable Text = ""
+       private var cached_text: nullable Text = null
+
+       private var init_complete = false
 
        # Last text drawn
        fun text: nullable Text do return cached_text
@@ -62,6 +74,8 @@ class TextSprites
                if text == cached_text then return
                cached_text = text
 
+               if not init_complete then return
+
                # Clean up last used sprites
                for s in sprites do if target_sprite_set.has(s) then target_sprite_set.remove s
                sprites.clear
@@ -73,6 +87,65 @@ class TextSprites
                # Register sprites to be drawn by `app.ui_camera`
                target_sprite_set.add_all sprites
        end
+
+       # Horizontal text alignment
+       #
+       # Use 0.0 to align left (the default), 0.5 to align in the center or
+       # 1.0 to align on the right.
+       #
+       # See: `valign`
+       var align = 0.0 is optional, writable
+
+       # Vertical text alignment
+       #
+       # Use 0.0 for top alignment (the default) where the text is under the `anchor`,
+       # 0.5 to vertically center the text on the `anchor` or
+       # or 1.0 to bottom align the text above the `anchor`.
+       #
+       # See: `align`
+       var valign = 0.0 is optional, writable
+
+       # Maximum width of each line of text
+       #
+       # The first word of each line is exempt and may overflow.
+       #
+       # The behavior when a line overflow depends on `wrap`.
+       var max_width: nullable Float is writable
+
+       # Maximum height of this block of text
+       #
+       # The first line is exempt and may overflow.
+       # Overflowing lines are cut.
+       var max_height: nullable Float is writable
+
+       # Should overflowing lines wrap to the next line?
+       #
+       # If `true`, the default, overflowing lines continue on the next line.
+       # Otherwise, lines are cut before overflowing.
+       var wrap = true is optional, writable
+
+       # Width of the currently displayed text
+       var width = 0.0
+
+       # Height of the currently displayed text
+       var height = 0.0
+
+       # Force drawing of the text sprites
+       #
+       # This method may be called after changing a setting (`align`, `wrap`, etc.)
+       # to update the displayed text.
+       fun force_redraw
+       do
+               var t = cached_text
+               cached_text = null
+               text = t
+       end
+
+       init
+       do
+               init_complete = true
+               force_redraw
+       end
 end
 
 # Partial line forward (U+008B)