When DrawTriangles is called and then WritePixels is called on a
sub-image, a panic happened. However, this panic actually happens
only when the graphics driver requires restoring (e.g. OpenGL ES
on Android). The situation was very limited, but this was a real
problem on Android.
This panic was introduced to prevent a rendering bug by a inmature
graphics drivers, but we should no longer need this. This change
just removes the panic.
Updates #292
This function was not called actually, so this is not a real problem.
However, this could be a potential problem for a future GLES driver (#292).
Updates #292Closes#2321
DrawTriangles was introduced at #1508, and apparently there is no
reason we should use ReplacePixels here. So, simplify the logic by
using only DrawTriangles.
This constant was set with some wrong assumptions:
1. On Android, recovering was needed.
2. On iOS, OpenGL ES was used when
a. The architecture was 386 or amd64 == an emulator is used
b. The build tag ebitengl was not specified
c. gomobile-build was used
3. On browsers, recovering was needed.
1., 2b, and 2c are correct.
2a. is not correct: Now emulators are available on all the
architectures with both Metal and OpenGL.
3. is not correct: Ebiten no longer recovers the contest lost.
Now, Ebiten can detect a context lost explicitly when
1. On Android
2. On iOS and on gomobile-build
(When gomobile-build is used, OpenGL should always be used)
Based on this fact, this change changes the constant to a variable,
and fixes the logic to set the variable.
With DirectX, the graphics driver cannot be determined until the
main loop starts, as a transparent window cannot be treated with
DirectX so far. On the other hand, compiling shaders requires a
graphics driver as it requires information about Y directions of
NDCs and framebuffers.
This change delays compiling shaders until the graphics commands
are actually executed in the main loop.
Updates #1007
Updates #2019
Allow overlapped regions at pixelsRecords.
This removes the members `last*` for caching. These were introduced
at 7e7751bd43, and apparently these
are no longer needed.
If regions by ReplacePixel are overlapped, this can panics. This can
happen only on Android, where a context lost can happen.
Thus, a sub-image cannot call a direct ReplacePixels. internal/buffer
has to care this.
