From 72ed6f2349432e95a9e0702664e6dea962a27855 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sun, 25 Oct 2009 17:09:32 +0000
Subject: [PATCH] Fix scissoring for too wide/high widgets

---
 include/gui2/RenderContext.hpp |  4 ++--
 src/gui2/RenderContext.cpp     | 27 ++++++++++++++++++++-------
 src/gui2/Window.cpp            |  2 +-
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/include/gui2/RenderContext.hpp b/include/gui2/RenderContext.hpp
index 7343cf2..4aaff21 100644
--- a/include/gui2/RenderContext.hpp
+++ b/include/gui2/RenderContext.hpp
@@ -36,7 +36,7 @@ namespace gui {
       RenderContext();
       ~RenderContext();
 
-      void push_origin(int x, int y);
+      void push_origin(const Widget* w);
       void pop_origin();
 
       void scissor(Widget* w);
@@ -53,7 +53,7 @@ namespace gui {
       Theme theme_;
       int origin_x, origin_y;
 
-      stack<pair<int, int> > origin_stack;
+      stack<const Widget*> origin_stack;
    };
    
 }
diff --git a/src/gui2/RenderContext.cpp b/src/gui2/RenderContext.cpp
index 78dfb54..2207180 100644
--- a/src/gui2/RenderContext.cpp
+++ b/src/gui2/RenderContext.cpp
@@ -45,16 +45,17 @@ RenderContext::~RenderContext()
    glPopAttrib();
 }
 
-void RenderContext::push_origin(int x, int y)
+void RenderContext::push_origin(const Widget* w)
 {
-   origin_x = x;
-   origin_y = y;
-   origin_stack.push(make_pair(x, y));
+   origin_x = w->x();
+   origin_y = w->y();
+   origin_stack.push(w);
 }
 
 void RenderContext::pop_origin()
 {
-   tie(origin_x, origin_y) = origin_stack.top();
+   origin_x = origin_stack.top()->x();
+   origin_y = origin_stack.top()->y();
    origin_stack.pop();
 }
 
@@ -112,7 +113,16 @@ void RenderContext::print(IFontPtr font, int x, int y, const string& s)
 
 void RenderContext::scissor(Widget* w)
 {
-   static int wh = getGameWindow()->height();
+   int wh = getGameWindow()->height();
+
+   const Widget* parent = origin_stack.empty() ? NULL : origin_stack.top();
+   int max_w, max_h;
+   if (parent) {
+      max_w = parent->width() - w->x();
+      max_h = parent->height() - w->y();
+   }
+   else
+      max_w = max_h = 100000;
    
    int x = w->x() - 1;
    int y = w->y() - 1;
@@ -120,5 +130,8 @@ void RenderContext::scissor(Widget* w)
 
    y = wh - y - w->height() - 1;
    
-   glScissor(x, y, w->width() + 1, w->height());
+   int width = min(w->width() + 1, max_w);
+   int height = min(w->height(), max_h);
+   
+   glScissor(x, y, width, height);
 }
diff --git a/src/gui2/Window.cpp b/src/gui2/Window.cpp
index 849ed03..da8278f 100644
--- a/src/gui2/Window.cpp
+++ b/src/gui2/Window.cpp
@@ -34,7 +34,7 @@ void Window::render(RenderContext& rc) const
    rc.border(x(), y(), width(), height(),
       rc.theme().border());
 
-   rc.push_origin(x(), y());
+   rc.push_origin(this);
 
    ContainerWidget::render(rc);
    
-- 
2.39.2