SDLOffScreenSurface.cc

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#include "SDLOffScreenSurface.hh"
#include "SDLVisibleSurface.hh"
#include "narrow.hh"
#include <cstring>
 
namespace openmsx {
 
SDLOffScreenSurface::SDLOffScreenSurface(const SDL_Surface& proto)
{
        gl::ivec2 size(proto.w, proto.h);
        calculateViewPort(size, size);
        setSDLPixelFormat(*proto.format);
 
        // SDL_CreateRGBSurface() allocates an internal buffer, on 32-bit
        // systems this buffer is only 8-bytes aligned. For some scalers (with
        // SSE(2) optimizations) we need a 16-byte aligned buffer. So now we
        // allocate the buffer ourselves and create the SDL_Surface with
        // SDL_CreateRGBSurfaceFrom().
        // Of course it would be better to get rid of SDL_Surface in the
        // OutputSurface interface.
 
        const PixelFormat& frmt = getPixelFormat();
        unsigned pitch2 = proto.w * frmt.getBytesPerPixel();
        assert((pitch2 % 16) == 0);
        unsigned bufSize = pitch2 * proto.h;
        buffer.resize(bufSize);
        ranges::fill(std::span{buffer.data(), bufSize}, 0);
        surface.reset(SDL_CreateRGBSurfaceFrom(
                buffer.data(), proto.w, proto.h, narrow<int>(frmt.getBpp()), narrow<int>(pitch2),
                frmt.getRmask(), frmt.getGmask(), frmt.getBmask(), frmt.getAmask()));
 
        setSDLSurface(surface.get());
 
        // Used (only?) by 'screenshot -with-osd'.
        renderer.reset(SDL_CreateSoftwareRenderer(surface.get()));
        setSDLRenderer(renderer.get());
}
 
void SDLOffScreenSurface::saveScreenshot(const std::string& filename)
{
        SDLVisibleSurface::saveScreenshotSDL(*this, filename);
}
 
void SDLOffScreenSurface::clearScreen()
{
        memset(surface->pixels, 0, size_t(surface->pitch) * surface->h);
}
 
} // namespace openmsx