Graphics flickering is not always due to incorrect VBL/timing

[mauiaaron]

Some graphics "flickering" glitches are manifesting (Airheart, Karateka, ...) due to flaws in how the emulator renders to its internal framebuffer. Fixes are slated for next Android release and will be added to mainline develop branch hopefully "soon".

There are other deeper flickering glitches due to incorrect timings. Correcting these will not be trivial but are being considered ;-)

[jvernet]

Latests changes add flickering to TEXT mode (try the French Touch demos: they whre working before).

[mauiaaron]

Yes I just noticed that. So I won't be bringing that commit to the main develop branch for now. I believe it is due to improper synchronization between the render thread and VBL timing. Compiling with -DVM_TRACING=1 can see the French demos writing to Mockingboard and then switching between MAIN and AUX memory (RAMRD switch).

For now I won't bring that commit to main develop branch ... it will stay on my personal experimental rebase branch until fixed and more tests are written =)

[mauiaaron]

@jvernet : you can apply the following patch to locally fix NSCT.dsk. I will need to figure out a better mid-term solution of course which should include more platform tests =)

diff --git a/src/display.c b/src/display.c
index 07a3576..de2af47 100644
--- a/src/display.c
+++ b/src/display.c
@@ -1232,6 +1232,7 @@ static inline void _currentPageAndBank(uint32_t currswitches, drawpage_mode_t mo

     *page = !!(currswitches & SS_PAGE2);
     *bank = !!(currswitches & SS_RAMRD);
+    *bank = 0;
 }

 uint8_t *video_currentFramebuffer(void) {

[mauiaaron]

Believe this is no longer an issue