revamped pixel output draft

2022-07-29 00:12:29 +03:00
parent 61018ab06d
commit c0e7afd79d
3 changed files with 29 additions and 23 deletions
@@ -39,8 +39,25 @@ function ESOPExtensions() {
        height = 48,
        vramOffset = vm.videoMemOffset,
        vramSize = vm.videoMemSize,
-        ctx = cnv.getContext('2d', {alpha: false})
+        ctx = cnv.getContext('2d', {alpha: false}),
+        xval = null, yval = null
    ctx.globalAlpha = 1
+    //setup pixel drawing ports
+    function pixelHook(port, coord, prev) {
+      if(port === 2) xval = coord
+      else if(port === 3) yval = coord
+      if(xval !== null && yval !== null) { //both coordinates set, update the pixel
+        var pxlOffset = yval * width + xval,
+            byteOffset = pxlOffset >>> 3,
+            bitOffset = 7 - pxlOffset + (byteOffset << 3),
+            vramvalue = vm.getram(vramOffset + byteOffset, 1)[0]
+        vm.setram(vramOffset + byteOffset, vramvalue | (1<<bitOffset))
+        xval = yval = null
+      }
+      vm.setdev(port, prev) //preserve the input value
+    }
+    vm.setWriteHook(2, pixelHook) //X
+    vm.setWriteHook(3, pixelHook) //Y
    //setup screen renderer
    function renderScreen() {
      var vram = vm.getram(vramOffset, vramSize),