Clearing alpha channel of a Form's framebuffer to 0.

Tweaking the particle editor theme to go with the alpha change.
Fixing Sean's fix of warnings in Font.
Supporting alignment and positioning of Forms.
Adding an important null-check in Theme.

gameplay/src/Container.cpp

@@ -264,7 +264,7 @@ void Container::draw(SpriteBatch* spriteBatch, const Rectangle& clip, bool needs
     if (_skin && needsClear)
     {
         GL_ASSERT( glEnable(GL_SCISSOR_TEST) );
-        GL_ASSERT( glClearColor(0, 0, 0, 1) );
+        GL_ASSERT( glClearColor(0, 0, 0, 0) );
         float clearY = targetHeight - _clearBounds.y - _clearBounds.height;
         GL_ASSERT( glScissor(_clearBounds.x, clearY,
             _clearBounds.width, _clearBounds.height) );

gameplay/src/Control.cpp

@@ -7,7 +7,7 @@ namespace gameplay
 
 Control::Control()
     : _id(""), _state(Control::NORMAL), _bounds(Rectangle::empty()), _clipBounds(Rectangle::empty()), _viewportClipBounds(Rectangle::empty()),
-        _dirty(true), _consumeTouchEvents(true), _listeners(NULL), _styleOverridden(false)
+    _dirty(true), _consumeTouchEvents(true), _listeners(NULL), _styleOverridden(false), _skin(NULL), _clearBounds(Rectangle::empty())
 {
 }
 
@@ -881,7 +881,7 @@ void Control::draw(SpriteBatch* spriteBatch, const Rectangle& clip, bool needsCl
     if (needsClear)
     {
         GL_ASSERT( glEnable(GL_SCISSOR_TEST) );
-        GL_ASSERT( glClearColor(0, 0, 0, 1) );
+        GL_ASSERT( glClearColor(0, 0, 0, 0) );
         GL_ASSERT( glScissor(_clearBounds.x, targetHeight - _clearBounds.y - _clearBounds.height,
             _clearBounds.width, _clearBounds.height) );
         GL_ASSERT( glClear(GL_COLOR_BUFFER_BIT) );

gameplay/src/Font.cpp

@@ -302,9 +302,9 @@ Font::Text* Font::createText(const char* text, const Rectangle& area, const Vect
                         {
                             // Simply copy values directly into the start of the index array
                             batch->_indices[batch->_vertexCount] = batch->_vertexCount;
-                            batch->_indices[batch->_vertexCount] = batch->_vertexCount + 1;
-                            batch->_indices[batch->_vertexCount] = batch->_vertexCount + 2;
-                            batch->_indices[batch->_vertexCount] = batch->_vertexCount + 3;
+                            batch->_indices[batch->_vertexCount + 1] = batch->_vertexCount + 1;
+                            batch->_indices[batch->_vertexCount + 2] = batch->_vertexCount + 2;
+                            batch->_indices[batch->_vertexCount + 3] = batch->_vertexCount + 3;
                             batch->_vertexCount += 4;
                             batch->_indexCount += 4;
                         }

gameplay/src/Form.cpp

@@ -93,6 +93,25 @@ Form* Form::create(const char* url)
     const char* styleName = formProperties->getString("style");
     form->initialize(theme->getStyle(styleName), formProperties);
 
+    // Alignment
+    if ((form->_alignment & Control::ALIGN_BOTTOM) == Control::ALIGN_BOTTOM)
+    {
+        form->_bounds.y = Game::getInstance()->getHeight() - form->_bounds.height;
+    }
+    else if ((form->_alignment & Control::ALIGN_VCENTER) == Control::ALIGN_VCENTER)
+    {
+        form->_bounds.y = Game::getInstance()->getHeight() * 0.5f - form->_bounds.height * 0.5f;
+    }
+
+    if ((form->_alignment & Control::ALIGN_RIGHT) == Control::ALIGN_RIGHT)
+    {
+        form->_bounds.x = Game::getInstance()->getWidth() - form->_bounds.width;
+    }
+    else if ((form->_alignment & Control::ALIGN_HCENTER) == Control::ALIGN_HCENTER)
+    {
+        form->_bounds.x = Game::getInstance()->getWidth() * 0.5f - form->_bounds.width * 0.5f;
+    }
+
     // Add all the controls to the form.
     form->addControls(theme, formProperties);
 
@@ -266,7 +285,108 @@ void Form::update()
 {
     if (isDirty())
     {
-        Container::update(Rectangle(0, 0, _bounds.width, _bounds.height), Vector2::zero());
+        _clearBounds.set(_absoluteClipBounds);
+
+        // Calculate the clipped bounds.
+        float x = 0;
+        float y = 0;
+        float width = _bounds.width;
+        float height = _bounds.height;
+
+        Rectangle clip(0, 0, _bounds.width, _bounds.height);
+
+        float clipX2 = clip.x + clip.width;
+        float x2 = clip.x + x + width;
+        if (x2 > clipX2)
+            width -= x2 - clipX2;
+
+        float clipY2 = clip.y + clip.height;
+        float y2 = clip.y + y + height;
+        if (y2 > clipY2)
+            height -= y2 - clipY2;
+
+        if (x < 0)
+        {
+            width += x;
+            x = -x;
+        }
+        else
+        {
+            x = 0;
+        }
+
+        if (y < 0)
+        {
+            height += y;
+            y = -y;
+        }
+        else
+        {
+            y = 0;
+        }
+
+        _clipBounds.set(x, y, width, height);
+
+        // Calculate the absolute bounds.
+        x = 0;
+        y = 0;
+        _absoluteBounds.set(x, y, _bounds.width, _bounds.height);
+
+        // Calculate the absolute viewport bounds.
+        // Absolute bounds minus border and padding.
+        const Theme::Border& border = getBorder(_state);
+        const Theme::Padding& padding = getPadding();
+
+        x += border.left + padding.left;
+        y += border.top + padding.top;
+        width = _bounds.width - border.left - padding.left - border.right - padding.right;
+        height = _bounds.height - border.top - padding.top - border.bottom - padding.bottom;
+
+        _viewportBounds.set(x, y, width, height);
+
+        // Calculate the clip area.
+        // Absolute bounds, minus border and padding,
+        // clipped to the parent container's clip area.
+        clipX2 = clip.x + clip.width;
+        x2 = x + width;
+        if (x2 > clipX2)
+            width = clipX2 - x;
+
+        clipY2 = clip.y + clip.height;
+        y2 = y + height;
+        if (y2 > clipY2)
+            height = clipY2 - y;
+
+        if (x < clip.x)
+        {
+            float dx = clip.x - x;
+            width -= dx;
+            x = clip.x;
+        }
+
+        if (y < clip.y)
+        {
+            float dy = clip.y - y;
+            height -= dy;
+            y = clip.y;
+        }
+ 
+        _viewportClipBounds.set(x, y, width, height);
+
+        _absoluteClipBounds.set(x - border.left - padding.left, y - border.top - padding.top,
+            width + border.left + padding.left + border.right + padding.right,
+            height + border.top + padding.top + border.bottom + padding.bottom);
+        if (_clearBounds.isEmpty())
+        {
+            _clearBounds.set(_absoluteClipBounds);
+        }
+
+        // Cache themed attributes for performance.
+        _skin = getSkin(_state);
+        _opacity = getOpacity(_state);
+
+        GP_ASSERT(_layout);
+        _layout->update(this);
     }
 }
 
@@ -293,7 +413,7 @@ void Form::draw()
 
         Game* game = Game::getInstance();
         Rectangle prevViewport = game->getViewport();
-        game->setViewport(Rectangle(_bounds.x, _bounds.y, _bounds.width, _bounds.height));
+        game->setViewport(Rectangle(0, 0, _bounds.width, _bounds.height));
 
         GP_ASSERT(_theme);
         _theme->setProjectionMatrix(_projectionMatrix);

gameplay/src/Layout.h

@@ -19,6 +19,7 @@ class Control;
 class Layout : public Ref
 {
     friend class Container;
+    friend class Form;
 
 public:
     /**

gameplay/src/Theme.cpp

@@ -271,7 +271,8 @@ Theme* Theme::create(const char* url)
                     if (!font)
                     {
                         font = normal->getFont();
-                        font->addRef();
+                        if (font)
+                            font->addRef();
                     }
 
                     unsigned int fontSize;