Add a graphic manager rendering 3D graphics for engines supporting
3D games. The manager is implemented using the 3D graphic managers
for Android and SDL as models.
Most probably Android and iOS can share much more of the code, but
that will be a separate work to refactor.
The iOSGraphics3dManager handles resize since the screen dimension
changes on rotation.
Games not supporting arbitary resolutions, e.g. Grim, are rendered
on an intermediate framebuffer with the size requested by the
engine and then rendered to the backbuffer (a framebuffer bound to
the renderbuffer) and stretched to the screen resolution off the
device.
This commit just adds the manager. It will be utilised in next
commit.
Update gitlab ci worker and update documentation.
The ios7 backend implements the graphic handling in the backend code.
iOS supports OpenGL through the OpenGL Framework since iOS 2.0. It's
marked as deprecated but is still shipped with the SDKs for iPhoneOS
and tvOS and will hopefully be so for some time.
The ios7 backend can therefore utilize the OpenGLGraphicsManager to
handle all graphics.
Implement an iOSGraphicsManager class that can be used in the ios7
backend. The iOSGraphicsManager will require some callback functions
in the ios7 backend. createOpenGLContext() will be called to ask the
backend to create an OpenGL context in which the graphic manager can
draw. The function returns the ID of the renderbuffer which shall be
used when creating the framebuffer object this differ iOS from other
platforms). A custom RenderBufferTarget class is added to address
this.
destroyOpenGLContext() will be called to make sure that the old GLES
context is not reused. notifyContextDestroy() does call the function
OpenGLContext.reset() but that will not destroy the context.
refreshScreen() will be called to ask the backend to present the
drawn graphics on the screen. getSystemHiDPIScreenFactor() is called
to get the screen scaling factor. getScreenWidth() and
getScreenHeight() are called to get the width and height of the
surface to draw on.
This commit adds the class but the ios7 backend doesn't make use of
it quite yet. To use it require the ios7 to be a child class of the
ModularGraphicsBackend. That change requires a lot of changes which
will be targeted in separate commits.
Update docportal and github ci worker to only disable the feature
opengl_classic_game since opengl and opengl_shaders are required to
compile the OpenGLGraphicsManager.
Xcode uses
/Applications/Xcode_10.3.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
by default. buildcache uses a wrapper for clang/clang++ and the action
prepends the wrapper to the PATH. But in order to use it, clang needs to
be called by its name alone, without full path.
