Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4a012f5d authored by Shih-Hsin Li's avatar Shih-Hsin Li Committed by Shih-hsin Li
Browse files

HWUI: reset buffer state after MakeCurrent 

MakeCurrent call is not guaranteed to reset read/draw buffer state of
default framebuffer unless it's the first time the context is bound.
When the default framebuffer transitions from EGL_NO_SURFACE to a surface,
it's buffer state might stay GL_NONE.

This change make sure default framebuffer buffer state is GL_BACK after
MakeCurrent.

Change-Id: I9d8a402c6e66e8eca177d8dec8208db3abb155f2
parent 23d97150

libs/hwui/pipeline/skia/SkiaOpenGLPipeline.cpp

+33 −0
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ SkiaOpenGLPipeline::~SkiaOpenGLPipeline() { 
}



MakeCurrentResult SkiaOpenGLPipeline::makeCurrent() {

    bool wasSurfaceless = mEglManager.isCurrent(EGL_NO_SURFACE);



    // In case the surface was destroyed (e.g. a previous trimMemory call) we

    // need to recreate it here.

    if (!isSurfaceReady() && mNativeWindow) {
@@ -63,6 +65,37 @@ MakeCurrentResult SkiaOpenGLPipeline::makeCurrent() { 
    if (!mEglManager.makeCurrent(mEglSurface, &error)) {

        return MakeCurrentResult::AlreadyCurrent;

    }



    // Make sure read/draw buffer state of default framebuffer is GL_BACK. Vendor implementations

    // disagree on the draw/read buffer state if the default framebuffer transitions from a surface

    // to EGL_NO_SURFACE and vice-versa. There was a related discussion within Khronos on this topic.

    // See https://cvs.khronos.org/bugzilla/show_bug.cgi?id=13534.

    // The discussion was not resolved with a clear consensus

    if (error == 0 && wasSurfaceless && mEglSurface != EGL_NO_SURFACE) {

        GLint curReadFB = 0;

        GLint curDrawFB = 0;

        glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING, &curReadFB);

        glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &curDrawFB);



        GLint buffer = GL_NONE;

        glBindFramebuffer(GL_FRAMEBUFFER, 0);

        glGetIntegerv(GL_DRAW_BUFFER0, &buffer);

        if (buffer == GL_NONE) {

            const GLenum drawBuffer = GL_BACK;

            glDrawBuffers(1, &drawBuffer);

        }



        glGetIntegerv(GL_READ_BUFFER, &buffer);

        if (buffer == GL_NONE) {

            glReadBuffer(GL_BACK);

        }



        glBindFramebuffer(GL_READ_FRAMEBUFFER, curReadFB);

        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, curDrawFB);



        GL_CHECKPOINT(LOW);

    }



    return error ? MakeCurrentResult::Failed : MakeCurrentResult::Succeeded;

}