Beispiel #1
0
void SkGL::SetPaint(const SkPaint& paint, bool isPremul, bool justAlpha) {
    if (justAlpha) {
        SkGL::SetAlpha(paint.getAlpha());
    } else {
        SkGL::SetColor(paint.getColor());
    }

    GLenum sm = GL_ONE;
    GLenum dm = GL_ONE_MINUS_SRC_ALPHA;

    SkXfermode* mode = paint.getXfermode();
    SkXfermode::Coeff sc, dc;
    if (mode && mode->asCoeff(&sc, &dc)) {
        sm = gXfermodeCoeff2Blend[sc];
        dm = gXfermodeCoeff2Blend[dc];
    }

    // hack for text, which is not-premul (afaik)
    if (!isPremul) {
        if (GL_ONE == sm) {
            sm = GL_SRC_ALPHA;
        }
    }

    glEnable(GL_BLEND);
    glBlendFunc(sm, dm);

    if (paint.isDither()) {
        glEnable(GL_DITHER);
    } else {
        glDisable(GL_DITHER);
    }
}