Slow rendering when at 1x zoom when using large screen

[btzy]

Is rendering playarea slow when zoomed out even with -O3?

[xsot]

Yes. I suspect it may be underperforming because of my gpu driver on linux. I can compare the performance on windows once we build the next release version.

[btzy]

Profiling results (on Windows/DirectX), when in selection mode with a sizable object selected: 1) Code spends most time inside PlayArea::render() - more than 76% of total execution time. 2) Of 22,734 samples inside PlayArea::render(), the large majority of them are in SDL_CreateTextureFromSurface(), and some of them are in renderPlayAreaSurface(). 3) Some goes to creating and freeing the surface.

playarea.cpp:

selectionaction.hpp

Things that can be done:

• Re-use a texture with SDL_TEXTUREACCESS_STREAMING and use SDL_LockTexture() to write directly to the SDL_Texture - eliminates (3) and hopefully reduces (2).
• Re-use the same SDL_Surface to eliminate (3).

[btzy]

Optimized sufficiently with a5369ae8fc3569e45eaad380246ceba51e026048 and da34d8bf5d2b68f9c0a6343fb465bc05d79faec1.