The "canvas" into which an application draws.
The Pebble OS graphics engine, inspired by several notable graphics systems, including Apple’s Quartz 2D and its predecessor QuickDraw, provides your app with a canvas into which to draw, namely, the graphics context. A graphics context is the target into which graphics functions can paint, using Pebble drawing routines (see Drawing Primitives, Drawing Paths and Drawing Text).
A graphics context holds a reference to the bitmap into which to paint. It also holds the current drawing state, like the current fill color, stroke color, clipping box, drawing box, compositing mode, and so on. The GContext struct is the type representing the graphics context.
For drawing in your Pebble watchface or watchapp, you won't need to create a GContext yourself. In most cases, it is provided by Pebble OS as an argument passed into a render callback (the .update_proc of a Layer).
Your app can’t call drawing functions at any given point in time: Pebble OS will request your app to render. Typically, your app will be calling out to graphics functions in the .update_proc callback of a Layer.
Sets the current stroke color of the graphics context.
The graphics context onto which to set the stroke color
The new stroke color
Sets the current fill color of the graphics context.
The graphics context onto which to set the fill color
The new fill color
Sets the current text color of the graphics context.
The graphics context onto which to set the text color
The new text color
Sets the current bitmap compositing mode of the graphics context.
At the moment, this only affects the bitmaps drawing operations - graphics_draw_bitmap_in_rect(), graphics_draw_rotated_bitmap, and anything that uses those APIs -, but it currently does not affect the filling or stroking operations.
The graphics context onto which to set the compositing mode
The new compositing mode
Sets whether antialiasing is applied to stroke drawing.
Default value is true.
The graphics context onto which to set the antialiasing
True = antialiasing enabled, False = antialiasing disabled
Sets the width of the stroke for drawing routines.
If stroke width of zero is passed, it will be ignored and will not change the value stored in GContext. Currently, only odd stroke_width values are supported. If an even value is passed in, the value will be stored as is, but the drawing routines will round down to the previous integral value when drawing. Default value is 1.
The graphics context onto which to set the stroke width
Width in pixels of the stroke.