SDLGLVisibleSurface.cc

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#include "SDLGLVisibleSurface.hh"
#include "SDLGLOffScreenSurface.hh"
#include "GLContext.hh"
#include "GLSnow.hh"
#include "OSDConsoleRenderer.hh"
#include "OSDGUILayer.hh"
#include "Display.hh"
#include "RenderSettings.hh"
#include "CliComm.hh"
#include "PNG.hh"
#include "build-info.hh"
#include "MemBuffer.hh"
#include "outer.hh"
#include "vla.hh"
#include "InitException.hh"
#include "unreachable.hh"
#include <memory>
 
namespace openmsx {
 
SDLGLVisibleSurface::SDLGLVisibleSurface(
                unsigned width, unsigned height,
                Display& display_,
                RTScheduler& rtScheduler_,
                EventDistributor& eventDistributor_,
                InputEventGenerator& inputEventGenerator_,
                CliComm& cliComm_,
                VideoSystem& videoSystem_)
        : SDLVisibleSurfaceBase(display_, rtScheduler_, eventDistributor_,
                                inputEventGenerator_, cliComm_, videoSystem_)
{
        SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
        SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
        SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 0);
        int flags = SDL_WINDOW_OPENGL;
        //flags |= SDL_RESIZABLE;
        createSurface(width, height, flags);
 
        // Create an OpenGL 3.3 Core profile
        SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
        SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
        SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
        glContext = SDL_GL_CreateContext(window.get());
        if (!glContext) {
                throw InitException(
                        "Failed to create openGL-3.3 context: ", SDL_GetError());
        }
 
        // From the glew documentation:
        //   GLEW obtains information on the supported extensions from the
        //   graphics driver. Experimental or pre-release drivers, however,
        //   might not report every available extension through the standard
        //   mechanism, in which case GLEW will report it unsupported. To
        //   circumvent this situation, the glewExperimental global switch can
        //   be turned on by setting it to GL_TRUE before calling glewInit(),
        //   which ensures that all extensions with valid entry points will be
        //   exposed.
        // The 'glewinfo' utility also sets this flag before reporting results,
        // so I believe it would cause less confusion to do the same here.
        glewExperimental = GL_TRUE;
 
        // Initialise GLEW library.
        GLenum glew_error = glewInit();
        if (glew_error != GLEW_OK) {
                throw InitException(
                        "Failed to init GLEW: ",
                        reinterpret_cast<const char*>(
                                glewGetErrorString(glew_error)));
        }
 
        // The created surface may be larger than requested.
        // If that happens, center the area that we actually use.
        int w, h;
        SDL_GL_GetDrawableSize(window.get(), &w, &h);
        calculateViewPort(gl::ivec2(width, height), gl::ivec2(w, h));
        auto [vx, vy] = getViewOffset();
        auto [vw, vh] = getViewSize();
        glViewport(vx, vy, vw, vh);
 
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(0, width, height, 0, -1, 1);
        glMatrixMode(GL_MODELVIEW);
 
        setOpenGlPixelFormat();
        gl::context = std::make_unique<gl::Context>(width, height);
 
        getDisplay().getRenderSettings().getVSyncSetting().attach(vSyncObserver);
        // set initial value
        vSyncObserver.update(getDisplay().getRenderSettings().getVSyncSetting());
}
 
SDLGLVisibleSurface::~SDLGLVisibleSurface()
{
        getDisplay().getRenderSettings().getVSyncSetting().detach(vSyncObserver);
 
        gl::context.reset();
        SDL_GL_DeleteContext(glContext);
}
 
void SDLGLVisibleSurface::saveScreenshot(const std::string& filename)
{
        saveScreenshotGL(*this, filename);
}
 
void SDLGLVisibleSurface::saveScreenshotGL(
        const OutputSurface& output, const std::string& filename)
{
        auto [x, y] = output.getViewOffset();
        auto [w, h] = output.getViewSize();
 
        VLA(const void*, rowPointers, h);
        MemBuffer<uint8_t> buffer(w * h * 3);
        for (int i = 0; i < h; ++i) {
                rowPointers[h - 1 - i] = &buffer[w * 3 * i];
        }
        glReadPixels(x, y, w, h, GL_RGB, GL_UNSIGNED_BYTE, buffer.data());
        PNG::save(w, h, rowPointers, filename);
}
 
void SDLGLVisibleSurface::finish()
{
        SDL_GL_SwapWindow(window.get());
}
 
std::unique_ptr<Layer> SDLGLVisibleSurface::createSnowLayer()
{
        return std::make_unique<GLSnow>(getDisplay());
}
 
std::unique_ptr<Layer> SDLGLVisibleSurface::createConsoleLayer(
                Reactor& reactor, CommandConsole& console)
{
        const bool openGL = true;
        auto [width, height] = getLogicalSize();
        return std::make_unique<OSDConsoleRenderer>(
                reactor, console, width, height, openGL);
}
 
std::unique_ptr<Layer> SDLGLVisibleSurface::createOSDGUILayer(OSDGUI& gui)
{
        return std::make_unique<GLOSDGUILayer>(gui);
}
 
std::unique_ptr<OutputSurface> SDLGLVisibleSurface::createOffScreenSurface()
{
        return std::make_unique<SDLGLOffScreenSurface>(*this);
}
 
void SDLGLVisibleSurface::VSyncObserver::update(const Setting& setting)
{
        auto& surface = OUTER(SDLGLVisibleSurface, vSyncObserver);
        auto& syncSetting = surface.getDisplay().getRenderSettings().getVSyncSetting();
        assert(&setting == &syncSetting); (void)setting;
 
        // for now, we assume that adaptive vsync is the best kind of vsync, so when
        // vsync is enabled, we attempt adaptive vsync.
        int interval = syncSetting.getBoolean() ? -1 : 0;
 
        if ((SDL_GL_SetSwapInterval(interval) < 0) && (interval == -1)) {
                // "Adaptive vsync" is not supported by all drivers. SDL
                // documentation suggests to fallback to "regular vsync" in
                // that case.
                SDL_GL_SetSwapInterval(1);
        }
}
 
} // namespace openmsx