replace dynamic_cast to static_cast,
This can be a controversial choice between optmization and clean code.
Obviously we know the converting types,
try avoiding a bit heavier casting some cases.
Change-Id: Id763e6d1db449a229a492ab5b1a901a195936152
We prefer to build up a tiny compact engine at memory rather than compatibility,
this engine is not considerd for end-users but designed for middle-level framework
and some low-level users.
Thus, we won't consider 64bits data size,
use explicit 32 bits data until coming next upgrade...
Change-Id: I0704d5f1e0eb909cccc10922bc5972e115fbbcc0
Introduce Result type for notifying caller more detailed info.
We should implement the result values for each apis, with practical values.
Change-Id: Ia47abcb56a8efca7094ac3eed0178aeac8aa2910
Obivously, we need to clear target before drawing.
Thus canvas request to renderers to clear buffer.
the implementation is upto backend engines.
Change-Id: Ib80da7f2260b021bcfed9fa13fb91c20218f9da0
introduce Canvas class to replace the CanvasBase.
now, SwCanvas, GlCanvas inherits this Canvas for polymorphism
and remove duplicated interfaces.
Change-Id: I65a87e3aa2289d04997930a54aeccd14f57dd73a
