More optimizing.

dvx/dvxApp.c

@@ -137,8 +137,6 @@ static void compositeAndFlush(AppContextT *ctx) {
             RectT popIsect;
 
             if (rectIntersect(dr, &popRect, &popIsect)) {
-                setClipRect(d, dr->x, dr->y, dr->w, dr->h);
-
                 // Find the window and menu
                 for (int32_t j = 0; j < ws->count; j++) {
                     if (ws->windows[j]->id == ctx->popup.windowId) {
@@ -202,8 +200,6 @@ static void compositeAndFlush(AppContextT *ctx) {
             RectT smIsect;
 
             if (rectIntersect(dr, &smRect, &smIsect)) {
-                setClipRect(d, dr->x, dr->y, dr->w, dr->h);
-
                 BevelStyleT smBevel;
                 smBevel.highlight = ctx->colors.windowHighlight;
                 smBevel.shadow    = ctx->colors.windowShadow;
@@ -465,10 +461,10 @@ static void dispatchEvents(AppContextT *ctx) {
     if (mx != ctx->prevMouseX || my != ctx->prevMouseY) {
         dirtyCursorArea(ctx, ctx->prevMouseX, ctx->prevMouseY);
         dirtyCursorArea(ctx, mx, my);
-    }
 
         // Update cursor shape based on what the mouse is hovering over
         updateCursorShape(ctx);
+    }
 
     // Handle active drag
     if (ctx->stack.dragWindow >= 0) {
@@ -1380,9 +1376,16 @@ static void pollAnsiTermWidgetsWalk(AppContextT *ctx, WidgetT *w, WindowT *win)
 static void pollKeyboard(AppContextT *ctx) {
     __dpmi_regs r;
 
-    // Check if key is available (INT 16h, enhanced function 11h)
+    // Read shift state once per poll (INT 16h, AH=12h)
-    while (1) {
     memset(&r, 0, sizeof(r));
+    r.x.ax = 0x1200;
+    __dpmi_int(0x16, &r);
+    int32_t shiftFlags = r.x.ax & 0xFF;
+    bool    shiftHeld  = (shiftFlags & 0x03) != 0; // left or right shift
+
+    // Process buffered keys
+    while (1) {
+        // Check if key is available (INT 16h, enhanced function 11h)
         r.x.ax = 0x1100;
         __dpmi_int(0x16, &r);
 
@@ -1392,7 +1395,6 @@ static void pollKeyboard(AppContextT *ctx) {
         }
 
         // Read the key (INT 16h, enhanced function 10h)
-        memset(&r, 0, sizeof(r));
         r.x.ax = 0x1000;
         __dpmi_int(0x16, &r);
 
@@ -1406,13 +1408,6 @@ static void pollKeyboard(AppContextT *ctx) {
             ascii = 0;
         }
 
-        // Read shift state (INT 16h, AH=12h — enhanced shift flags)
-        memset(&r, 0, sizeof(r));
-        r.x.ax = 0x1200;
-        __dpmi_int(0x16, &r);
-        int32_t shiftFlags = r.x.ax & 0xFF;
-        bool    shiftHeld  = (shiftFlags & 0x03) != 0; // left or right shift
-
         // Alt+Tab / Shift+Alt+Tab — cycle windows
         // Alt+Tab: scancode=0xA5, ascii=0x00
         if (ascii == 0 && scancode == 0xA5) {

dvx/dvxComp.c

@@ -77,12 +77,15 @@ void dirtyListMerge(DirtyListT *dl) {
         return;
     }
 
+    // Single-pass O(N²): for each rect, try to merge it into an
+    // earlier rect.  When a merge succeeds the merged rect may now
+    // overlap others, so restart the inner scan for that slot.
+    for (int32_t i = 0; i < dl->count; i++) {
         bool merged = true;
 
         while (merged) {
             merged = false;
 
-        for (int32_t i = 0; i < dl->count; i++) {
             for (int32_t j = i + 1; j < dl->count; j++) {
                 if (rectsOverlapOrAdjacent(&dl->rects[i], &dl->rects[j], DIRTY_MERGE_GAP)) {
                     rectUnion(&dl->rects[i], &dl->rects[j], &dl->rects[i]);
@@ -104,15 +107,12 @@ void dirtyListMerge(DirtyListT *dl) {
 void flushRect(DisplayT *d, const RectT *r) {
     int32_t bpp = d->format.bytesPerPixel;
 
+    // Caller (compositeAndFlush) already clips to screen bounds
     int32_t x = r->x;
     int32_t y = r->y;
     int32_t w = r->w;
     int32_t h = r->h;
 
-    if (__builtin_expect(x < 0, 0)) { w += x; x = 0; }
-    if (__builtin_expect(y < 0, 0)) { h += y; y = 0; }
-    if (__builtin_expect(x + w > d->width, 0)) { w = d->width - x; }
-    if (__builtin_expect(y + h > d->height, 0)) { h = d->height - y; }
     if (__builtin_expect(w <= 0 || h <= 0, 0)) { return; }
 
     int32_t  rowBytes = w * bpp;

dvx/dvxWidget.h

@@ -576,6 +576,9 @@ int32_t wgtAnsiTermRepaint(WidgetT *w, int32_t *outY, int32_t *outH);
 // Mark a widget (and ancestors) for relayout and repaint
 void wgtInvalidate(WidgetT *w);
 
+// Repaint only — skip measure/layout (use for visual-only changes)
+void wgtInvalidatePaint(WidgetT *w);
+
 // Set/get widget text (label, button, textInput, etc.)
 void wgtSetText(WidgetT *w, const char *text);
 const char *wgtGetText(const WidgetT *w);

dvx/widgets/widgetAnsiTerm.c

@@ -1553,7 +1553,7 @@ void widgetAnsiTermOnKey(WidgetT *w, int32_t key, int32_t mod) {
         if (ansiTermHasSelection(w)) {
             ansiTermCopySelection(w);
             ansiTermClearSelection(w);
-            wgtInvalidate(w);
+            wgtInvalidatePaint(w);
             return;
         }
 
@@ -1563,7 +1563,7 @@ void widgetAnsiTermOnKey(WidgetT *w, int32_t key, int32_t mod) {
     // Ctrl+V: paste from clipboard to terminal
     if (key == 0x16 && (mod & KEY_MOD_CTRL)) {
         ansiTermPasteToComm(w);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1645,7 +1645,7 @@ void widgetAnsiTermOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.ansiTerm.commWrite(w->as.ansiTerm.commCtx, buf, len);
     }
 
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 }
 
 
@@ -1822,8 +1822,18 @@ void widgetAnsiTermPaint(WidgetT *w, DisplayT *d, const BlitOpsT *ops, const Bit
     // Determine if viewing live terminal or scrollback
     bool viewingLive = (w->as.ansiTerm.scrollPos == sbCount);
 
-    // Render character cells row by row using bulk renderer
+    // Render character cells row by row using bulk renderer.
+    // Only repaint rows marked dirty; 0xFFFFFFFF means all rows.
+    uint32_t dirty = w->as.ansiTerm.dirtyRows;
+    if (dirty == 0) {
+        dirty = 0xFFFFFFFF;
+    }
+
     for (int32_t row = 0; row < rows; row++) {
+        if (row < 32 && !(dirty & (1U << row))) {
+            continue;
+        }
+
         int32_t lineIndex = w->as.ansiTerm.scrollPos + row;
         const uint8_t *lineData = ansiTermGetLine(w, lineIndex);
 
@@ -1838,6 +1848,8 @@ void widgetAnsiTermPaint(WidgetT *w, DisplayT *d, const BlitOpsT *ops, const Bit
         ansiTermPaintSelRow(w, d, ops, font, row, baseX, baseY);
     }
 
+    w->as.ansiTerm.dirtyRows = 0;
+
     // Draw scrollbar
     int32_t sbX = baseX + cols * cellW;
     int32_t sbY = baseY;

dvx/widgets/widgetButton.c

@@ -59,7 +59,7 @@ void widgetButtonOnKey(WidgetT *w, int32_t key, int32_t mod) {
     if (key == ' ' || key == 0x0D) {
         w->as.button.pressed = true;
         sKeyPressedBtn = w;
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
     }
 }
 

dvx/widgets/widgetCanvas.c

@@ -709,7 +709,7 @@ void widgetCanvasOnMouse(WidgetT *hit, WidgetT *root, int32_t vx, int32_t vy) {
     hit->as.canvas.lastX = cx;
     hit->as.canvas.lastY = cy;
 
-    wgtInvalidate(hit);
+    wgtInvalidatePaint(hit);
 }
 
 

dvx/widgets/widgetCheckbox.c

@@ -64,7 +64,7 @@ void widgetCheckboxOnKey(WidgetT *w, int32_t key, int32_t mod) {
             w->onChange(w);
         }
 
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
     }
 }
 

dvx/widgets/widgetComboBox.c

@@ -154,7 +154,7 @@ void widgetComboBoxOnKey(WidgetT *w, int32_t key, int32_t mod) {
                 }
             }
 
-            wgtInvalidate(w);
+            wgtInvalidatePaint(w);
             return;
         }
 
@@ -167,7 +167,7 @@ void widgetComboBoxOnKey(WidgetT *w, int32_t key, int32_t mod) {
                 }
             }
 
-            wgtInvalidate(w);
+            wgtInvalidatePaint(w);
             return;
         }
 
@@ -194,7 +194,7 @@ void widgetComboBoxOnKey(WidgetT *w, int32_t key, int32_t mod) {
                 w->onChange(w);
             }
 
-            wgtInvalidate(w);
+            wgtInvalidatePaint(w);
             return;
         }
     }
@@ -213,7 +213,7 @@ void widgetComboBoxOnKey(WidgetT *w, int32_t key, int32_t mod) {
             w->as.comboBox.listScrollPos = w->as.comboBox.hoverIdx;
         }
 
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -426,7 +426,7 @@ void widgetComboBoxPaintPopup(WidgetT *w, DisplayT *d, const BlitOpsT *ops, cons
             rectFill(d, ops, popX + 2, iy, textW + TEXT_INPUT_PAD * 2, font->charHeight, ibg);
         }
 
-        drawText(d, ops, font, textX, iy, items[idx], ifg, ibg, idx == hoverIdx);
+        drawText(d, ops, font, textX, iy, items[idx], ifg, ibg, false);
     }
 }
 

dvx/widgets/widgetDropdown.c

@@ -166,7 +166,7 @@ void widgetDropdownOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
     }
 
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 }
 
 
@@ -280,6 +280,6 @@ void widgetDropdownPaintPopup(WidgetT *w, DisplayT *d, const BlitOpsT *ops, cons
             rectFill(d, ops, popX + 2, iy, textW + TEXT_INPUT_PAD * 2, font->charHeight, ibg);
         }
 
-        drawText(d, ops, font, textX, iy, items[idx], ifg, ibg, idx == hoverIdx);
+        drawText(d, ops, font, textX, iy, items[idx], ifg, ibg, false);
     }
 }

dvx/widgets/widgetEvent.c

@@ -192,21 +192,21 @@ void widgetOnMouse(WindowT *win, int32_t x, int32_t y, int32_t buttons) {
         sDrawingCanvas->as.canvas.lastX = -1;
         sDrawingCanvas->as.canvas.lastY = -1;
         sDrawingCanvas = NULL;
-        wgtInvalidate(root);
+        wgtInvalidatePaint(root);
         return;
     }
 
     // Handle canvas drawing (mouse move while pressed)
     if (sDrawingCanvas && (buttons & 1)) {
         widgetCanvasOnMouse(sDrawingCanvas, root, x, y);
-        wgtInvalidate(root);
+        wgtInvalidatePaint(root);
         return;
     }
 
     // Handle slider drag release
     if (sDragSlider && !(buttons & 1)) {
         sDragSlider = NULL;
-        wgtInvalidate(root);
+        wgtInvalidatePaint(root);
         return;
     }
 
@@ -242,7 +242,7 @@ void widgetOnMouse(WindowT *win, int32_t x, int32_t y, int32_t buttons) {
                     sDragSlider->onChange(sDragSlider);
                 }
 
-                wgtInvalidate(root);
+                wgtInvalidatePaint(root);
             }
         }
 
@@ -272,7 +272,7 @@ void widgetOnMouse(WindowT *win, int32_t x, int32_t y, int32_t buttons) {
             }
         }
 
-        wgtInvalidate(sPressedButton);
+        wgtInvalidatePaint(sPressedButton);
         sPressedButton = NULL;
         return;
     }
@@ -302,7 +302,7 @@ void widgetOnMouse(WindowT *win, int32_t x, int32_t y, int32_t buttons) {
                 sPressedButton->as.button.pressed = over;
             }
 
-            wgtInvalidate(sPressedButton);
+            wgtInvalidatePaint(sPressedButton);
         }
 
         return;
@@ -376,7 +376,7 @@ void widgetOnMouse(WindowT *win, int32_t x, int32_t y, int32_t buttons) {
         }
 
         sOpenPopup = NULL;
-        wgtInvalidate(root);
+        wgtInvalidatePaint(root);
         // Fall through to normal click handling
     }
 

dvx/widgets/widgetImage.c

@@ -141,7 +141,7 @@ void widgetImageOnMouse(WidgetT *w, WidgetT *root, int32_t vx, int32_t vy) {
     (void)vx;
     (void)vy;
     w->as.image.pressed = true;
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 
     if (w->onClick) {
         w->onClick(w);

dvx/widgets/widgetImageButton.c

@@ -77,7 +77,7 @@ void widgetImageButtonOnKey(WidgetT *w, int32_t key, int32_t mod) {
     if (key == ' ' || key == 0x0D) {
         w->as.imageButton.pressed = true;
         sKeyPressedBtn = w;
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
     }
 }
 

dvx/widgets/widgetListBox.c

@@ -156,7 +156,7 @@ void widgetListBoxOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->onChange(w);
     }
 
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 }
 
 
@@ -292,7 +292,7 @@ void widgetListBoxPaint(WidgetT *w, DisplayT *d, const BlitOpsT *ops, const Bitm
             rectFill(d, ops, w->x + LISTBOX_BORDER, iy, contentW, font->charHeight, ibg);
         }
 
-        drawText(d, ops, font, innerX, iy, w->as.listBox.items[idx], ifg, ibg, idx == w->as.listBox.selectedIdx);
+        drawText(d, ops, font, innerX, iy, w->as.listBox.items[idx], ifg, ibg, false);
     }
 
     // Draw scrollbar

dvx/widgets/widgetOps.c

@@ -250,6 +250,40 @@ void wgtInvalidate(WidgetT *w) {
 }
 
 
+// ============================================================
+// wgtInvalidatePaint
+// ============================================================
+//
+// Lightweight repaint — skips measure/layout/scrollbar management.
+// Use when only visual state changed (slider value, cursor blink,
+// selection highlight, checkbox toggle) but widget sizes are stable.
+
+void wgtInvalidatePaint(WidgetT *w) {
+    if (!w || !w->window) {
+        return;
+    }
+
+    WidgetT *root = w;
+
+    while (root->parent) {
+        root = root->parent;
+    }
+
+    AppContextT *ctx = (AppContextT *)root->userData;
+
+    if (!ctx) {
+        return;
+    }
+
+    // Repaint without measure/layout
+    RectT fullRect = {0, 0, w->window->contentW, w->window->contentH};
+    widgetOnPaint(w->window, &fullRect);
+    w->window->contentDirty = true;
+
+    dvxInvalidateWindow(ctx, w->window);
+}
+
+
 // ============================================================
 // wgtPaint
 // ============================================================

dvx/widgets/widgetRadio.c

@@ -92,7 +92,7 @@ void widgetRadioOnKey(WidgetT *w, int32_t key, int32_t mod) {
             }
         }
 
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
     } else if (key == (0x50 | 0x100) || key == (0x4D | 0x100)) {
         // Down or Right — next radio in group
         if (w->parent && w->parent->type == WidgetRadioGroupE) {
@@ -115,7 +115,7 @@ void widgetRadioOnKey(WidgetT *w, int32_t key, int32_t mod) {
                     next->parent->onChange(next->parent);
                 }
 
-                wgtInvalidate(next);
+                wgtInvalidatePaint(next);
             }
         }
     } else if (key == (0x48 | 0x100) || key == (0x4B | 0x100)) {
@@ -139,7 +139,7 @@ void widgetRadioOnKey(WidgetT *w, int32_t key, int32_t mod) {
                     prev->parent->onChange(prev->parent);
                 }
 
-                wgtInvalidate(prev);
+                wgtInvalidatePaint(prev);
             }
         }
     }

dvx/widgets/widgetSlider.c

@@ -119,7 +119,7 @@ void widgetSliderOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->onChange(w);
     }
 
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 }
 
 

dvx/widgets/widgetTextInput.c

@@ -697,7 +697,7 @@ done:
         }
     }
 
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 }
 
 
@@ -948,7 +948,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         textAreaOffToRowCol(buf, *pLen, pRow, pCol);
         w->as.textArea.desiredCol = *pCol;
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -996,7 +996,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1023,7 +1023,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1067,7 +1067,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1105,7 +1105,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1144,7 +1144,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1181,7 +1181,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1197,7 +1197,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.textArea.desiredCol = *pCol;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1213,7 +1213,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.textArea.desiredCol = *pCol;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1229,7 +1229,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
 
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1245,7 +1245,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
 
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1256,7 +1256,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.textArea.desiredCol = 0;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1267,7 +1267,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.textArea.desiredCol = *pCol;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1284,7 +1284,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         *pCol = w->as.textArea.desiredCol < lineL ? w->as.textArea.desiredCol : lineL;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1301,7 +1301,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         *pCol = w->as.textArea.desiredCol < lineL ? w->as.textArea.desiredCol : lineL;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1313,7 +1313,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.textArea.desiredCol = 0;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1324,7 +1324,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         w->as.textArea.desiredCol = *pCol;
         SEL_END();
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -1361,7 +1361,7 @@ void widgetTextAreaOnKey(WidgetT *w, int32_t key, int32_t mod) {
         }
 
         textAreaEnsureVisible(w, visRows, visCols);
-        wgtInvalidate(w);
+        wgtInvalidatePaint(w);
         return;
     }
 
@@ -2520,5 +2520,5 @@ adjustScroll:
         }
     }
 
-    wgtInvalidate(w);
+    wgtInvalidatePaint(w);
 }