From e5949582e6b5d60f9a4aa1285668efdb598ed28b Mon Sep 17 00:00:00 2001
From: falkTX <falktx@falktx.com>
Date: Wed, 11 Oct 2023 15:18:12 +0200
Subject: [PATCH] Set auto-scale-factor early, cleaner GL setup

Signed-off-by: falkTX <falktx@falktx.com>
---
 dgl/src/Cairo.cpp             |  7 +------
 dgl/src/OpenGL.cpp            | 35 +++++++++--------------------------
 dgl/src/WindowPrivateData.cpp |  8 ++++++--
 3 files changed, 16 insertions(+), 34 deletions(-)

diff --git a/dgl/src/Cairo.cpp b/dgl/src/Cairo.cpp
index 1a5b69ec..d913c4e8 100644
--- a/dgl/src/Cairo.cpp
+++ b/dgl/src/Cairo.cpp
@@ -784,18 +784,13 @@ void TopLevelWidget::PrivateData::display()
 
     cairo_matrix_t matrix;
     cairo_get_matrix(handle, &matrix);
+    cairo_translate(handle, 0, 0);
 
     // full viewport size
     if (window.pData->autoScaling)
-    {
-        cairo_translate(handle, 0, 0);
         cairo_scale(handle, autoScaleFactor, autoScaleFactor);
-    }
     else
-    {
-        cairo_translate(handle, 0, 0);
         cairo_scale(handle, 1.0, 1.0);
-    }
 
     // main widget drawing
     self->onDisplay();
diff --git a/dgl/src/OpenGL.cpp b/dgl/src/OpenGL.cpp
index 00fbbf6b..43d096e9 100644
--- a/dgl/src/OpenGL.cpp
+++ b/dgl/src/OpenGL.cpp
@@ -707,26 +707,21 @@ void SubWidget::PrivateData::display(const uint width, const uint height, const
     else if (needsFullViewportForDrawing || (absolutePos.isZero() && self->getSize() == Size<uint>(width, height)))
     {
         // full viewport size
-        glViewport(0,
-                   -static_cast<int>(height * autoScaleFactor - height + 0.5),
-                   static_cast<int>(width * autoScaleFactor + 0.5),
-                   static_cast<int>(height * autoScaleFactor + 0.5));
+        glViewport(0, 0, static_cast<int>(width), static_cast<int>(height));
     }
     else
     {
         // set viewport pos
         glViewport(static_cast<int>(absolutePos.getX() * autoScaleFactor + 0.5),
-                   -static_cast<int>(std::round((height * autoScaleFactor - height)
-                                     + (absolutePos.getY() * autoScaleFactor))),
-                   static_cast<int>(std::round(width * autoScaleFactor)),
-                   static_cast<int>(std::round(height * autoScaleFactor)));
+                   -static_cast<int>(absolutePos.getY() * autoScaleFactor + 0.5),
+                   static_cast<int>(width),
+                   static_cast<int>(height));
 
         // then cut the outer bounds
         glScissor(static_cast<int>(absolutePos.getX() * autoScaleFactor + 0.5),
-                  static_cast<int>(height - std::round((static_cast<int>(self->getHeight()) + absolutePos.getY())
-                                                       * autoScaleFactor)),
-                  static_cast<int>(std::round(self->getWidth() * autoScaleFactor)),
-                  static_cast<int>(std::round(self->getHeight() * autoScaleFactor)));
+                  static_cast<int>(height - (self->getHeight() + absolutePos.getY()) * autoScaleFactor + 0.5),
+                  static_cast<int>(self->getWidth() * autoScaleFactor + 0.5),
+                  static_cast<int>(self->getHeight() * autoScaleFactor + 0.5));
 
         glEnable(GL_SCISSOR_TEST);
         needsDisableScissor = true;
@@ -752,26 +747,14 @@ void TopLevelWidget::PrivateData::display()
     const uint width  = size.getWidth();
     const uint height = size.getHeight();
 
-    const double autoScaleFactor = window.pData->autoScaleFactor;
-
     // full viewport size
-    if (window.pData->autoScaling)
-    {
-        glViewport(0,
-                   -static_cast<int>(height * autoScaleFactor - height + 0.5),
-                   static_cast<int>(width * autoScaleFactor + 0.5),
-                   static_cast<int>(height * autoScaleFactor + 0.5));
-    }
-    else
-    {
-        glViewport(0, 0, static_cast<int>(width), static_cast<int>(height));
-    }
+    glViewport(0, 0, static_cast<int>(width), static_cast<int>(height));
 
     // main widget drawing
     self->onDisplay();
 
     // now draw subwidgets if there are any
-    selfw->pData->displaySubWidgets(width, height, autoScaleFactor);
+    selfw->pData->displaySubWidgets(width, height, window.pData->autoScaleFactor);
 }
 
 // -----------------------------------------------------------------------
diff --git a/dgl/src/WindowPrivateData.cpp b/dgl/src/WindowPrivateData.cpp
index 7e3e5c83..2f0f4d75 100644
--- a/dgl/src/WindowPrivateData.cpp
+++ b/dgl/src/WindowPrivateData.cpp
@@ -577,9 +577,13 @@ void Window::PrivateData::onPuglConfigure(const double width, const double heigh
         const double scaleVertical   = height / static_cast<double>(minHeight);
         autoScaleFactor = scaleHorizontal < scaleVertical ? scaleHorizontal : scaleVertical;
     }
+    else
+    {
+        autoScaleFactor = 1.0;
+    }
 
-    const uint uwidth = static_cast<uint>(width + 0.5);
-    const uint uheight = static_cast<uint>(height + 0.5);
+    const uint uwidth = static_cast<uint>(width / autoScaleFactor + 0.5);
+    const uint uheight = static_cast<uint>(height / autoScaleFactor + 0.5);
 
     self->onReshape(uwidth, uheight);