graphics: scanline scroll and the splash screen demonstrating the feature

assets/bios/tsvmbios.js

@@ -4,12 +4,29 @@ graphics.resetPalette();graphics.setBackground(0,0,0);
 let logo = gzip.decomp(base64.atob("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"));
 
 // display logo in kickin' ass-style of panasonic
-//let m=56;let r=()=>{let i=Math.random()*2-1;return(i<0)?i-1:i+1};
+// hide entire framebuffer with black text to hide the slow image drawing
-//let o=[];for(let y=0;y<164;y++)o[y]=Math.round(r()*560/m)|0;
-//for(let p=0;p<=1120/m;p++){for(let y=0;y<164;y++){for(let x=0;x<560;x++)
-//{let f=y*560+x;let d=x+m*o[y];if(d>=0&&d<560)graphics.plotPixel(d,95+y,logo[f]);}
-//if(o[y]!=0)o[y]-=Math.sign(o[y]);}}
 
+con.color_pair(0,0);
+for(let i=0;i<2560;i++)graphics.putSymbolAt(1+(i/80)|0,1+(i%80),239);
+// draw logo
+for(let i=0;i<logo.length;i++){graphics.plotPixel(i%560,95+(i/560)|0,logo[i])}
+// scramble lines
+let m=4;let r=()=>{let i=Math.random()*2-1;return(i<0)?i-1:i+1};
+let o=[];for(let y=0;y<164;y++){
+let k=Math.round(r()*560/m)|0;
+o.push(k);graphics.setLineOffset(95+y,k*m);}
+// unhide screen
+graphics.setBackground(0,0,15);con.color_pair(239,255);
+for(let i=0;i<2560;i++)graphics.putSymbolAt(1+(i/80)|0,1+(i%80),0);
+// unscramble
+let tmr=0;let n=560*2;while(n>0){
+for(let y=0;y<164;y++){o[y]-=Math.sign(o[y]);graphics.setLineOffset(95+y,o[y]*m);}
+// wait for timer
+tmr=sys.nanoTime();while(sys.nanoTime()-tmr<250000*m)Math.sqrt(tmr) // waste some cpu time
+n-=m;}
+
+
+/*
 // display logo in mundane, true-to-msx way
 graphics.setFramebufferScroll(0,-164);
 // hide entire framebuffer with black text to hide the slow image drawing
@@ -27,6 +44,7 @@ let tmr=sys.nanoTime();
 let tlen=1073741824;
 while(1){let tdiff=sys.nanoTime()-tmr;if(tdiff>=tlen)break;
 graphics.setFramebufferScroll(0,-((1.0-tdiff/tlen)*164)|0);}
+*/
 
 // show how much ram is there
 con.color_pair(239,4);
@@ -57,7 +75,7 @@ Object.freeze(_BIOS);
 tmr = sys.nanoTime();
 while (sys.nanoTime() - tmr < 2147483648) sys.spin();
 // clear screen
-graphics.clearPixels(255);
+graphics.clearPixels(255);con.color_pair(254,255);
 con.clear();con.move(1,1);
 
 ///////////////////////////////////////////////////////////////////////////////

src/net/torvald/tsvm/GraphicsJSR223Delegate.kt

@@ -1,6 +1,7 @@
 package net.torvald.tsvm
 
 import net.torvald.UnsafeHelper
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.toUint
 import net.torvald.tsvm.peripheral.GraphicsAdapter
 import net.torvald.tsvm.peripheral.fmod
 
@@ -60,6 +61,22 @@ class GraphicsJSR223Delegate(val vm: VM) {
         }
     }
 
+    fun setLineOffset(line: Int, offset: Int) {
+        getFirstGPU()?.let {
+            it.poke(250900L + 2*line, offset.shr(8).toByte()) // absolutely not USHR
+            it.poke(250901L + 2*line, offset.toByte())
+        }
+    }
+
+    fun getLineOffset(line: Int): Int {
+        getFirstGPU()?.let {
+            var xoff = it.peek(250900L + 2*line)!!.toUint().shl(8) or it.peek(250901L + 2*line)!!.toUint()
+            if (xoff.and(0x8000) != 0) xoff = xoff or 0xFFFF0000.toInt()
+            return xoff
+        }
+        return 0
+    }
+
     fun getPixelDimension(): IntArray {
         getFirstGPU()?.let { return intArrayOf(it.framebuffer.width, it.framebuffer.height) }
         return intArrayOf(-1, -1)
@@ -139,14 +156,14 @@ class GraphicsJSR223Delegate(val vm: VM) {
     private fun GraphicsAdapter._loadSprite(spriteNum: Int, ptr: Int) {
         UnsafeHelper.memcpy(
             vm.usermem.ptr + ptr,
-            (this.spriteAndTextArea).ptr + (260 * spriteNum) + 4,
+            (this.textArea).ptr + (260 * spriteNum) + 4,
             256
         )
     }
 
     private fun GraphicsAdapter._storeSprite(spriteNum: Int, ptr: Int) {
         UnsafeHelper.memcpy(
-            (this.spriteAndTextArea).ptr + (260 * spriteNum) + 4,
+            (this.textArea).ptr + (260 * spriteNum) + 4,
             vm.usermem.ptr + ptr,
             256
         )

src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt

@@ -7,6 +7,7 @@ import com.badlogic.gdx.graphics.g2d.TextureRegion
 import com.badlogic.gdx.graphics.glutils.FrameBuffer
 import com.badlogic.gdx.math.Matrix4
 import net.torvald.UnsafeHelper
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.toUint
 import net.torvald.tsvm.AppLoader
 import net.torvald.tsvm.VM
 import net.torvald.tsvm.kB
@@ -14,7 +15,6 @@ import net.torvald.tsvm.peripheral.GraphicsAdapter.Companion.DRAW_SHADER_FRAG
 import java.io.InputStream
 import java.io.OutputStream
 import kotlin.experimental.and
-import kotlin.math.roundToInt
 
 data class AdapterConfig(
     val theme: String,
@@ -59,6 +59,7 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     protected val TAB_SIZE = 8
 
     internal val framebuffer = Pixmap(WIDTH, HEIGHT, Pixmap.Format.Alpha)
+    internal val framebuffer2 = Pixmap(WIDTH, HEIGHT, Pixmap.Format.Alpha)
     protected var rendertex = Texture(1, 1, Pixmap.Format.RGBA8888)
     internal val paletteOfFloats = FloatArray(1024) {
         val rgba = DEFAULT_PALETTE[it / 4]
@@ -68,8 +69,8 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     protected val chrrom0 = Texture("./assets/"+config.chrRomPath)
     protected val faketex: Texture
 
-    internal val spriteAndTextArea = UnsafeHelper.allocate(10660L)
+    internal val textArea = UnsafeHelper.allocate(7682)
-    protected val unusedArea = ByteArray(92)
+    internal val unusedArea = UnsafeHelper.allocate(1024)
 
     protected val paletteShader = AppLoader.loadShaderInline(DRAW_SHADER_VERT, config.paletteShader)
     protected val textShader = AppLoader.loadShaderInline(DRAW_SHADER_VERT, config.fragShader)
@@ -100,15 +101,15 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     private val outFBObatch = SpriteBatch()
 
 
-    private val memTextCursorPosOffset = 2978L
+    private val memTextCursorPosOffset = 0L
-    private val memTextForeOffset = 2980L
+    private val memTextForeOffset = 2L
-    private val memTextBackOffset = 2980L + 2560
+    private val memTextBackOffset = 2L + 2560
-    private val memTextOffset = 2980L + 2560 + 2560
+    private val memTextOffset = 2L + 2560 + 2560
     private val TEXT_AREA_SIZE = TEXT_COLS * TEXT_ROWS
 
     override var rawCursorPos: Int
-        get() = spriteAndTextArea.getShort(memTextCursorPosOffset).toInt()
+        get() = textArea.getShort(memTextCursorPosOffset).toInt()
-        set(value) { spriteAndTextArea.setShort(memTextCursorPosOffset, value.toShort()) }
+        set(value) { textArea.setShort(memTextCursorPosOffset, value.toShort()) }
 
     override fun getCursorPos() = rawCursorPos % TEXT_COLS to rawCursorPos / TEXT_COLS
 
@@ -144,13 +145,15 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
         outFBObatch.projectionMatrix = m
 
 
-
         framebuffer.blending = Pixmap.Blending.None
+        framebuffer2.blending = Pixmap.Blending.None
         textForePixmap.blending = Pixmap.Blending.None
         textBackPixmap.blending = Pixmap.Blending.None
         framebuffer.setColor(-1)
         framebuffer.fill()
 
+        unusedArea.fillWith(0)
+
         val pm = Pixmap(1, 1, Pixmap.Format.RGBA8888)
         pm.drawPixel(0, 0, -1)
         faketex = Texture(pm)
@@ -159,10 +162,10 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
         // initialise with NONZERO value; value zero corresponds to opaque black, and it will paint the whole screen black
         // when in text mode, and that's undesired behaviour
         // -1 is preferred because it points to the colour CLEAR, and it's constant.
-        spriteAndTextArea.fillWith(-1)
+        textArea.fillWith(-1)
         // fill text area with 0
         for (k in 0 until TEXT_ROWS * TEXT_COLS) {
-            spriteAndTextArea[k + memTextOffset] = 0
+            textArea[k + memTextOffset] = 0
         }
 
         if (theme.contains("color")) {
@@ -173,7 +176,7 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
 
         setCursorPos(0, 0)
 
-        println(framebuffer.pixels.limit())
+        println("Framebuffer pixels limit: ${framebuffer.pixels.limit()}")
     }
 
     override fun peek(addr: Long): Byte? {
@@ -184,8 +187,8 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
             250897L -> framebufferScrollX.ushr(8).toByte()
             250898L -> framebufferScrollY.toByte()
             250899L -> framebufferScrollY.ushr(8).toByte()
-            in 250880 until 250972 -> unusedArea[adi - 250880]
+            in 250880 until 250880+1024 -> unusedArea[addr - 250880]
-            in 250972 until 261632 -> spriteAndTextArea[addr - 250972]
+            in 253950 until 261632 -> textArea[addr - 253950]
             in 261632 until 262144 -> peekPalette(adi - 261632)
             in 0 until VM.HW_RESERVE_SIZE -> {
                 println("[GraphicsAdapter] mirroring with input address $addr")
@@ -204,15 +207,15 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
                 framebuffer.pixels.put(adi, byte)
             }
             250883L -> {
-                unusedArea[adi - 250880] = byte
+                unusedArea[addr - 250880] = byte
                 runCommand(byte)
             }
             250896L -> framebufferScrollX = framebufferScrollX.and(0xFFFFFF00.toInt()).or(bi)
             250897L -> framebufferScrollX = framebufferScrollX.and(0xFFFF00FF.toInt()).or(bi shl 8)
             250898L -> framebufferScrollY = framebufferScrollY.and(0xFFFFFF00.toInt()).or(bi)
             250899L -> framebufferScrollY = framebufferScrollY.and(0xFFFF00FF.toInt()).or(bi shl 8)
-            in 250880 until 250972 -> unusedArea[adi - 250880] = byte
+            in 250880 until 250880+1024 -> unusedArea[addr - 250880] = byte
-            in 250972 until 261632 -> spriteAndTextArea[addr - 250972] = byte
+            in 253950 until 261632 -> textArea[addr - 253950] = byte
             in 261632 until 262144 -> pokePalette(adi - 261632, byte)
             in 0 until VM.HW_RESERVE_SIZE -> {
                 println("[GraphicsAdapter] mirroring with input address $addr")
@@ -287,9 +290,9 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
 
     override fun putChar(x: Int, y: Int, text: Byte, foreColour: Byte, backColour: Byte) {
         val textOff = toTtyTextOffset(x, y)
-        spriteAndTextArea[memTextForeOffset + textOff] = foreColour
+        textArea[memTextForeOffset + textOff] = foreColour
-        spriteAndTextArea[memTextBackOffset + textOff] = backColour
+        textArea[memTextBackOffset + textOff] = backColour
-        spriteAndTextArea[memTextOffset + textOff] = text
+        textArea[memTextOffset + textOff] = text
     }
 
     override fun cursorUp(arg: Int) {
@@ -338,11 +341,11 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
                 val foreBits = ttyFore or ttyFore.shl(8) or ttyFore.shl(16) or ttyFore.shl(24)
                 val backBits = ttyBack or ttyBack.shl(8) or ttyBack.shl(16) or ttyBack.shl(24)
                 for (i in 0 until TEXT_COLS * TEXT_ROWS step 4) {
-                    spriteAndTextArea.setInt(memTextForeOffset + i, foreBits)
+                    textArea.setInt(memTextForeOffset + i, foreBits)
-                    spriteAndTextArea.setInt(memTextBackOffset + i, backBits)
+                    textArea.setInt(memTextBackOffset + i, backBits)
-                    spriteAndTextArea.setInt(memTextOffset + i, 0)
+                    textArea.setInt(memTextOffset + i, 0)
                 }
-                spriteAndTextArea.setShort(memTextCursorPosOffset, 0)
+                textArea.setShort(memTextCursorPosOffset, 0)
             }
             else -> TODO()
         }
@@ -358,24 +361,24 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     override fun scrollUp(arg: Int) {
         val displacement = arg.toLong() * TEXT_COLS
         UnsafeHelper.memcpy(
-            spriteAndTextArea.ptr + memTextOffset + displacement,
+            textArea.ptr + memTextOffset + displacement,
-            spriteAndTextArea.ptr + memTextOffset,
+            textArea.ptr + memTextOffset,
             TEXT_AREA_SIZE - displacement
         )
         UnsafeHelper.memcpy(
-            spriteAndTextArea.ptr + memTextBackOffset + displacement,
+            textArea.ptr + memTextBackOffset + displacement,
-            spriteAndTextArea.ptr + memTextBackOffset,
+            textArea.ptr + memTextBackOffset,
             TEXT_AREA_SIZE - displacement
         )
         UnsafeHelper.memcpy(
-            spriteAndTextArea.ptr + memTextForeOffset + displacement,
+            textArea.ptr + memTextForeOffset + displacement,
-            spriteAndTextArea.ptr + memTextForeOffset,
+            textArea.ptr + memTextForeOffset,
             TEXT_AREA_SIZE - displacement
         )
         for (i in 0 until displacement) {
-            spriteAndTextArea[memTextOffset + TEXT_AREA_SIZE - displacement + i] = 0
+            textArea[memTextOffset + TEXT_AREA_SIZE - displacement + i] = 0
-            spriteAndTextArea[memTextBackOffset + TEXT_AREA_SIZE - displacement + i] = ttyBack.toByte()
+            textArea[memTextBackOffset + TEXT_AREA_SIZE - displacement + i] = ttyBack.toByte()
-            spriteAndTextArea[memTextForeOffset + TEXT_AREA_SIZE - displacement + i] = ttyFore.toByte()
+            textArea[memTextForeOffset + TEXT_AREA_SIZE - displacement + i] = ttyFore.toByte()
         }
     }
 
@@ -383,24 +386,24 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     override fun scrollDown(arg: Int) {
         val displacement = arg.toLong() * TEXT_COLS
         UnsafeHelper.memcpy(
-            spriteAndTextArea.ptr + memTextOffset,
+            textArea.ptr + memTextOffset,
-            spriteAndTextArea.ptr + memTextOffset + displacement,
+            textArea.ptr + memTextOffset + displacement,
             TEXT_AREA_SIZE - displacement
         )
         UnsafeHelper.memcpy(
-            spriteAndTextArea.ptr + memTextBackOffset,
+            textArea.ptr + memTextBackOffset,
-            spriteAndTextArea.ptr + memTextBackOffset + displacement,
+            textArea.ptr + memTextBackOffset + displacement,
             TEXT_AREA_SIZE - displacement
         )
         UnsafeHelper.memcpy(
-            spriteAndTextArea.ptr + memTextForeOffset,
+            textArea.ptr + memTextForeOffset,
-            spriteAndTextArea.ptr + memTextForeOffset + displacement,
+            textArea.ptr + memTextForeOffset + displacement,
             TEXT_AREA_SIZE - displacement
         )
         for (i in 0 until displacement) {
-            spriteAndTextArea[memTextOffset + TEXT_AREA_SIZE + i] = 0
+            textArea[memTextOffset + TEXT_AREA_SIZE + i] = 0
-            spriteAndTextArea[memTextBackOffset + TEXT_AREA_SIZE + i] = ttyBack.toByte()
+            textArea[memTextBackOffset + TEXT_AREA_SIZE + i] = ttyBack.toByte()
-            spriteAndTextArea[memTextForeOffset + TEXT_AREA_SIZE + i] = ttyFore.toByte()
+            textArea[memTextForeOffset + TEXT_AREA_SIZE + i] = ttyFore.toByte()
         }
     }
 
@@ -570,8 +573,9 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     override fun dispose() {
         //testTex.dispose()
         framebuffer.dispose()
+        framebuffer2.dispose()
         rendertex.dispose()
-        spriteAndTextArea.destroy()
+        textArea.destroy()
         textForePixmap.dispose()
         textBackPixmap.dispose()
         textPixmap.dispose()
@@ -585,6 +589,7 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
         try { textBackTex.dispose() } catch (_: Throwable) {}
 
         chrrom0.dispose()
+        unusedArea.destroy()
     }
 
     private var textCursorBlinkTimer = 0f
@@ -594,8 +599,27 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
     private var decayColor = Color(1f, 1f, 1f, 1f - glowDecay)
 
     open fun render(delta: Float, uiBatch: SpriteBatch, xoff: Float, yoff: Float) {
+        framebuffer2.setColor(-1);framebuffer2.fill()
+        for (y in 0 until 448) {
+            var xoff = unusedArea[20L + 2*y].toUint().shl(8) or unusedArea[20L + 2*y + 1].toUint()
+            if (xoff.and(0x8000) != 0) xoff = xoff or 0xFFFF0000.toInt()
+            val xs = (0+xoff).coerceIn(0,559) .. (559+xoff).coerceIn(0,559)
+
+            if (xoff in -559..559) {
+                for (x in xs) {
+                    //framebuffer2.drawPixel(x, y, framebuffer.getPixel(x + xs.first - xoff, y))
+
+                    // this only works because framebuffer is guaranteed to be 8bpp
+                    framebuffer2.pixels.put(y*560+x,
+                        framebuffer.pixels.get(y*560 + (x - xoff).coerceIn(0, 559))
+                    )
+                }
+            }
+        }
+
+
         rendertex.dispose()
-        rendertex = Texture(framebuffer, Pixmap.Format.RGBA8888, false)
+        rendertex = Texture(framebuffer2, Pixmap.Format.RGBA8888, false)
 
         val texOffX = (framebufferScrollX fmod framebuffer.width) * -1f
         val texOffY = (framebufferScrollY fmod framebuffer.height) * 1f
@@ -657,12 +681,12 @@ open class GraphicsAdapter(val vm: VM, val config: AdapterConfig, val sgr: Super
                             val drawCursor = blinkCursor && textCursorIsOn && cx == x && cy == y
                             val addr = y.toLong() * TEXT_COLS + x
                             val char =
-                                if (drawCursor) 0xFF else spriteAndTextArea[memTextOffset + addr].toInt().and(255)
+                                if (drawCursor) 0xFF else textArea[memTextOffset + addr].toInt().and(255)
                             var back =
-                                if (drawCursor) ttyBack else spriteAndTextArea[memTextBackOffset + addr].toInt()
+                                if (drawCursor) ttyBack else textArea[memTextBackOffset + addr].toInt()
                                     .and(255)
                             var fore =
-                                if (drawCursor) ttyFore else spriteAndTextArea[memTextForeOffset + addr].toInt()
+                                if (drawCursor) ttyFore else textArea[memTextForeOffset + addr].toInt()
                                     .and(255)
 
                             textPixmap.setColor(Color(0f, 0f, char / 255f, 1f))