Fixed #10: Added TerminalMaterial

README.md

@@ -78,12 +78,9 @@ This library provides three mechanisms to do that:
 
 ### `TerminalText`
 
-This is a material for use with Indigo's standard `Text` primitive.
+This is a material for use with Indigo's standard `Text` primitive. In addition to foreground and background `TerminalText` also supports a solid colour dropshadow.
 
-Looks great but has two problems:
-
-1. Changing colors mid-artwork (e.g. setting the text red and the border blue) is a pain, you need to use another `Text` instance and make them line up!.
-2. This process allocates a lot during the rendering process, and probably won't scale very well.
+Looks great but has a glaring problem: Changing colors mid-artwork (e.g. setting the text red and the border blue) is a pain, you need to use another `Text` instance and make them line up!
 
 Great for pop-up menus, and monochrome sections of ASCII art, or maps that aren't too big. After that, a new strategy may be needed.
 
@@ -98,9 +95,7 @@ The terminal emulators are the basis of the library, and provide a simple 'termi
 
 ### `TerminalEmulator` with `TerminalEntity`
 
-This is the most flexible way to render, but not the fastest.
-
-The `TerminalEmulator` in conjunction with the `TerminalEntity` works in a completely different way. Here a special shader is going to draw all the ASCII characters out in a continuous image, and you can interleave colors any time you like with no performance cost. This moves processing costs away from the rendering pipeline but incurs a penalty on the CPU side.
+The `TerminalEmulator` in conjunction with the `TerminalEntity` works in a completely different way to the other methods. Here a special shader (does not support foreground alpha or drop shadows!) is going to draw all the ASCII characters out in a continuous image, and you can interleave colors any time you like with no performance cost. This moves processing costs away from the rendering pipeline but incurs a penalty on the CPU side.
 
 The terminal emulator... emulates a simple terminal interface allowing you to put and get characters. Terminals can be merged and drawn.
 
@@ -124,6 +119,10 @@ This is as capable as the previous method, but does not have the 4096 tile limit
 
 [Example](https://github.com/PurpleKingdomGames/roguelike-starterkit/blob/main/demo/src/main/scala/demo/CloneTilesScene.scala)
 
+### `TerminalMaterial`
+
+This material is a near drop-in replacement for `TerminalText`. It does not support the drop shadow feature, but has a leaner implementation for performance sensitive contexts. Supposed to be used with the `TerminalEmulator`'s `toCloneTiles` method.
+
 ## Extras
 
 The starter kit also provides:

demo/src/main/scala/demo/CloneTilesScene.scala

@@ -60,7 +60,7 @@ object CloneTilesScene extends Scene[Unit, Unit, Unit]:
   ): Outcome[SceneUpdateFragment] =
     val tiles =
       terminal.toCloneTiles(CloneId("demo"), Point.zero, RoguelikeTiles.Size10x10.charCrops) { (fg, bg) =>
-        Graphic(10, 10, TerminalText(Assets.tileMap, fg, bg))
+        Graphic(10, 10, TerminalMaterial(Assets.tileMap, fg, bg))
       }
 
     Outcome(

demo/src/main/scala/demo/RogueLikeGame.scala

@@ -34,6 +34,7 @@ object RogueLikeGame extends IndigoGame[Unit, Unit, Unit, Unit]:
         .withShaders(
           TerminalEntity.shader(maxTileCount),
           TerminalText.standardShader,
+          TerminalMaterial.standardShader,
           TerminalTextScene.customShader(ShaderId("my shader"))
         )
         .withSubSystems(FPSCounter(Point(10, 350)))

roguelike-starterkit/src/main/scala/io/indigoengine/roguelike/starterkit/package.scala

@@ -18,6 +18,9 @@ val MapTile: terminal.MapTile.type = terminal.MapTile
 type TerminalText = terminal.TerminalText
 val TerminalText: terminal.TerminalText.type = terminal.TerminalText
 
+type TerminalMaterial = terminal.TerminalMaterial
+val TerminalMaterial: terminal.TerminalMaterial.type = terminal.TerminalMaterial
+
 type TerminalClones = terminal.TerminalClones
 val TerminalClones: terminal.TerminalClones.type = terminal.TerminalClones
 

roguelike-starterkit/src/main/scala/io/indigoengine/roguelike/starterkit/terminal/TerminalMaterial.scala

@@ -0,0 +1,124 @@
+package io.indigoengine.roguelike.starterkit.terminal
+
+import indigo.*
+import indigo.syntax.shaders.*
+
+/** `TerminalMaterial` is a revised and leaner version of `TerminalText`, aimed at use with
+  * `CloneTiles`. It removes the dubious drop shadow functionality, requires less shader data, and
+  * has simpler shader logic.
+  */
+final case class TerminalMaterial(
+    tileMap: AssetName,
+    foreground: RGBA,
+    background: RGBA,
+    mask: RGBA,
+    shaderId: Option[ShaderId]
+) extends Material:
+
+  def withForeground(newColor: RGBA): TerminalMaterial =
+    this.copy(foreground = newColor)
+  def withForeground(newColor: RGB): TerminalMaterial =
+    withForeground(newColor.toRGBA)
+
+  def withBackground(newColor: RGBA): TerminalMaterial =
+    this.copy(background = newColor)
+  def withBackground(newColor: RGB): TerminalMaterial =
+    withBackground(newColor.toRGBA)
+
+  def withMask(newColor: RGBA): TerminalMaterial =
+    this.copy(mask = newColor)
+  def withMask(newColor: RGB): TerminalMaterial =
+    withMask(newColor.toRGBA)
+
+  def withShaderId(newShaderId: ShaderId): TerminalMaterial =
+    this.copy(shaderId = Option(newShaderId))
+
+  def toShaderData: ShaderData =
+    ShaderData(
+      shaderId.getOrElse(TerminalMaterial.shaderId),
+      Batch(
+        UniformBlock(
+          UniformBlockName("RogueLikeTextData"),
+          Batch(
+            Uniform("FOREGROUND") -> foreground.asVec4,
+            Uniform("BACKGROUND") -> background.asVec4,
+            Uniform("MASK")       -> mask.asVec4
+          )
+        )
+      ),
+      Some(tileMap),
+      None,
+      None,
+      None
+    )
+
+object TerminalMaterial:
+
+  val defaultMask: RGBA =
+    RGBA.Magenta
+
+  val shaderId: ShaderId =
+    ShaderId("roguelike standard terminal material")
+
+  def standardShader: UltravioletShader =
+    UltravioletShader.entityFragment(
+      shaderId,
+      EntityShader.fragment[ShaderImpl.Env](
+        ShaderImpl.frag,
+        ShaderImpl.Env.ref
+      )
+    )
+
+  def apply(tileMap: AssetName): TerminalMaterial =
+    TerminalMaterial(tileMap, RGBA.White, RGBA.Zero, defaultMask, None)
+
+  def apply(tileMap: AssetName, color: RGBA): TerminalMaterial =
+    TerminalMaterial(tileMap, color, RGBA.Zero, defaultMask, None)
+
+  def apply(tileMap: AssetName, foreground: RGBA, background: RGBA): TerminalMaterial =
+    TerminalMaterial(tileMap, foreground, background, defaultMask, None)
+
+  def apply(
+      tileMap: AssetName,
+      foreground: RGBA,
+      background: RGBA,
+      mask: RGBA
+  ): TerminalMaterial =
+    TerminalMaterial(tileMap, foreground, background, mask, None)
+
+  object ShaderImpl:
+
+    import ultraviolet.syntax.*
+
+    final case class Env(
+        FOREGROUND: vec4,
+        BACKGROUND: vec4,
+        MASK: vec4
+    ) extends FragmentEnvReference
+
+    object Env:
+      val ref =
+        Env(vec4(0.0f), vec4(0.0f), vec4(0.0f))
+
+    final case class RogueLikeTextData(
+        FOREGROUND: vec4,
+        BACKGROUND: vec4,
+        MASK: vec4
+    )
+
+    inline def frag: Shader[Env, Unit] =
+      Shader[Env] { env =>
+        ubo[RogueLikeTextData]
+
+        // Calculate the distance from the color to the mask, and snap to 0.0 or 1.0 over a low threshold.
+        def maskAmount(color: vec4, mask: vec4): Float =
+          val v = abs(color - mask)
+          step(0.001f, v.x + v.y + v.z + v.w)
+
+        def fragment(color: vec4): vec4 =
+          val bg   = vec4(env.BACKGROUND.rgb * env.BACKGROUND.a, env.BACKGROUND.a)
+          val tint = env.CHANNEL_0 * env.FOREGROUND
+          val fg   = vec4(tint.rgb * tint.a, tint.a)
+
+          mix(bg, fg, maskAmount(env.CHANNEL_0, env.MASK))
+      }

roguelike-starterkit/src/main/scala/io/indigoengine/roguelike/starterkit/terminal/TerminalText.scala

@@ -3,6 +3,8 @@ package io.indigoengine.roguelike.starterkit.terminal
 import indigo.*
 import indigo.syntax.shaders.*
 
+/** The original Terminal text material, designed for use with `Text` entities. Supports approximate drop shadows.
+  */
 final case class TerminalText(
     tileMap: AssetName,
     foreground: RGBA,