Fix game sample

tiny-doc/src/docs/asciidoc/sample/pong.lua

@@ -305,6 +305,8 @@ function Ball:valid_move()
     return self.y > 256
 end
 
+local player = nil
+
 function _init()
     transition = new(GameOut)
 
@@ -315,13 +317,10 @@ function _init()
         cooldown = 0
     }
 
-    dt = 1 / 60
-    longueurCode = 100
-    longueurSegment = 10
-    numSegments = longueurCode / longueurSegment
-    gravite = 29.8
-    rigidite = 1 -- 0.8
-    amortissement = 0.9
+    player = new(Player)
+    for y=216,248,8 do
+        player:createPaddle(y)
+    end
 
     raquettes = {
         create_raquette(216),

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/GameEngine.kt

@@ -506,7 +506,7 @@ class GameEngine(
     }
 
     /**
-     * Will render the actual operations on the screen.
+     * Will render the actual operations in the frame buffer
      */
     fun render() {
         val last = ops.lastOrNull() ?: return
@@ -531,7 +531,7 @@ class GameEngine(
             ops.add(op)
         }
 
-        // Render operations on the screen.
+        // Render operations in the GPU frame buffer
         platform.render(renderContext, ops)
 
         // The framebuffer has been rendered.
@@ -555,6 +555,16 @@ class GameEngine(
         return renderFrame?.getPixel(x, y) ?: ColorPalette.TRANSPARENT_INDEX
     }
 
+    override fun readFrame(): FrameBuffer {
+        if (renderFrame == null) {
+            render()
+            renderFrame = platform.readRender(renderContext)
+        }
+        val copy = FrameBuffer(frameBuffer.width, frameBuffer.height, frameBuffer.gamePalette)
+        renderFrame?.copyInto(copy.colorIndexBuffer)
+        return copy
+    }
+
     override fun end() {
         soundManager.destroy()
     }

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/GameResourceAccess.kt

@@ -54,6 +54,11 @@ interface GameResourceAccess {
         y: Int,
     ): ColorIndex
 
+    /**
+     * Read the full screen
+     */
+    fun readFrame(): FrameBuffer
+
     /**
      * Access a sprite sheet by its index.
      */

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/graphic/ColorPalette.kt

@@ -189,6 +189,6 @@ class ColorPalette(colors: List<HexColor>) {
 
     companion object {
         private val TRANSPARENT = byteArrayOf(0, 0, 0, 0)
-        val TRANSPARENT_INDEX = 0
+        const val TRANSPARENT_INDEX = 0
     }
 }

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/lua/GfxLib.kt

@@ -6,7 +6,6 @@ import com.github.mingdx.tiny.doc.TinyFunction
 import com.github.mingdx.tiny.doc.TinyLib
 import com.github.minigdx.tiny.engine.GameOptions
 import com.github.minigdx.tiny.engine.GameResourceAccess
-import com.github.minigdx.tiny.graphic.PixelArray
 import com.github.minigdx.tiny.render.operations.CameraOperation
 import com.github.minigdx.tiny.render.operations.ClipOperation
 import com.github.minigdx.tiny.render.operations.DitheringOperation
@@ -72,9 +71,9 @@ class GfxLib(private val resourceAccess: GameResourceAccess, private val gameOpt
     internal inner class pset : ThreeArgFunction() {
         @TinyCall("set the color index at the coordinate (x,y).")
         override fun call(
-            @TinyArg("x")arg1: LuaValue,
-            @TinyArg("y")arg2: LuaValue,
-            @TinyArg("color")arg3: LuaValue,
+            @TinyArg("x") arg1: LuaValue,
+            @TinyArg("y") arg2: LuaValue,
+            @TinyArg("color") arg3: LuaValue,
         ): LuaValue {
             resourceAccess.frameBuffer.pixel(arg1.checkint(), arg2.checkint(), arg3.checkint())
             resourceAccess.addOp(FrameBufferOperation)
@@ -86,8 +85,8 @@ class GfxLib(private val resourceAccess: GameResourceAccess, private val gameOpt
     internal inner class pget : TwoArgFunction() {
         @TinyCall("get the color index at the coordinate (x,y).")
         override fun call(
-            @TinyArg("x")arg1: LuaValue,
-            @TinyArg("y")arg2: LuaValue,
+            @TinyArg("x") arg1: LuaValue,
+            @TinyArg("y") arg2: LuaValue,
         ): LuaValue {
             val x = min(max(0, arg1.checkint()), gameOptions.width - 1)
             val y = min(max(0, arg2.checkint()), gameOptions.height - 1)
@@ -111,30 +110,25 @@ class GfxLib(private val resourceAccess: GameResourceAccess, private val gameOpt
         override fun call(
             @TinyArg("sheet") arg: LuaValue,
         ): LuaValue {
-            val frameBuffer = resourceAccess.frameBuffer
-            val copy =
-                PixelArray(frameBuffer.width, frameBuffer.height).apply {
-                    copyFrom(frameBuffer.colorIndexBuffer) { index, _, _ -> index }
-                }
+            val (index, name) = if (arg.isstring()) {
+                val index = resourceAccess.spritesheet(arg.tojstring()) ?: resourceAccess.newSpritesheetIndex()
+                index to arg.tojstring()
+            } else {
+                val spriteSheet = resourceAccess.spritesheet(arg.checkint())
+                arg.toint() to (spriteSheet?.name ?: "frame_buffer_${arg.toint()}")
+            }
+
+            val frameBuffer = resourceAccess.readFrame()
+            val sheet = SpriteSheet(
+                0,
+                index,
+                name,
+                ResourceType.GAME_SPRITESHEET,
+                frameBuffer.colorIndexBuffer,
+                frameBuffer.width,
+                frameBuffer.height,
+            )
 
-            val (index, name) =
-                if (arg.isstring()) {
-                    val index = resourceAccess.spritesheet(arg.tojstring()) ?: resourceAccess.newSpritesheetIndex()
-                    index to arg.tojstring()
-                } else {
-                    val spriteSheet = resourceAccess.spritesheet(arg.checkint())
-                    arg.toint() to (spriteSheet?.name ?: "frame_buffer_${arg.toint()}")
-                }
-            val sheet =
-                SpriteSheet(
-                    0,
-                    index,
-                    name,
-                    ResourceType.GAME_SPRITESHEET,
-                    copy,
-                    copy.width,
-                    copy.height,
-                )
             resourceAccess.spritesheet(sheet)
             return arg
         }

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/platform/Platform.kt

@@ -130,6 +130,9 @@ interface Platform {
         ops: List<RenderOperation>,
     )
 
+    /**
+     * Read the full rendered screen into a frame.
+     */
     fun readRender(renderContext: RenderContext): RenderFrame
 
     /**

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/render/gl/OpenGLFrame.kt

@@ -7,6 +7,7 @@ import com.github.minigdx.tiny.engine.GameOptions
 import com.github.minigdx.tiny.graphic.PixelArray
 import com.github.minigdx.tiny.graphic.PixelFormat
 import com.github.minigdx.tiny.render.RenderFrame
+import kotlin.math.max
 
 class OpenGLFrame(
     private val buffer: ByteBuffer,
@@ -28,12 +29,12 @@ class OpenGLFrame(
         // the bottom line is the first line in the buffer
         for (x in 0 until gameOptions.width) {
             for (y in 0 until gameOptions.height) {
-                buffer.position = (x + y * gameOptions.width) * PixelFormat.RGBA
+                buffer.position = (x + (max(0, gameOptions.height - 1 - y)) * gameOptions.width) * PixelFormat.RGBA
 
                 readBytes(buffer, tmp)
 
                 val colorIndex = gameOptions.colors().getColorIndex(tmp)
-                pixelArray.set(x, (gameOptions.height - 1) - y, colorIndex)
+                pixelArray.set(x, y, colorIndex)
             }
         }
 

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/render/gl/OperationsShader.kt

@@ -128,6 +128,7 @@ class OperationsShader(
                 // Get the straight color
                 index
             }
+
             val color = colors.getRGBA(pal)
             colorPaletteBuffer[pos++] = color[0]
             colorPaletteBuffer[pos++] = color[1]

tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/render/operations/FrameBufferOperation.kt

@@ -2,7 +2,7 @@ package com.github.minigdx.tiny.render.operations
 
 import com.github.minigdx.tiny.render.RenderUnit
 
-object FrameBufferOperation : RenderOperation {
+data object FrameBufferOperation : RenderOperation {
     override val target: RenderUnit = RenderUnit.CPU
 
     override fun mergeWith(previousOperation: RenderOperation?): Boolean {

tiny-sample/_tiny.json

@@ -28,7 +28,6 @@
     "#FF77A8",
     "#FFCCAA"
   ],
-  "sounds": ["test.mid"],
   "scripts": [
     "pong.lua"
   ],