fix a scissor bug in the GLES-on-top-of copybit code

}

struct clipRectRegion : public copybit_region_t {

    clipRectRegion(ogles_context_t* c) {

    clipRectRegion(ogles_context_t* c) 

    {

        scissor_t const* scissor = &c->rasterizer.state.scissor;

        r.l = scissor->left;

        r.t = scissor->top;

        r.r = scissor->right;

        r.b = scissor->bottom;

        next = iterate; 

        int x = c->viewport.scissor.x;

        int y = c->viewport.scissor.y;

        r.l = x;

        r.t = y;

        r.r = x + c->viewport.scissor.w;

        r.b = y + c->viewport.scissor.h;

        firstTime = true;

    }

private:

    static int iterate(copybit_region_t const * self, copybit_rect_t* rect) {

        clipRectRegion* myself = (clipRectRegion*) self;

        if (myself->firstTime) {

            myself->firstTime = false;

            *rect = myself->r;

        *rect = static_cast<clipRectRegion const*>(self)->r;

        const_cast<copybit_region_t *>(self)->next = iterate_done;

        return 1;

    }

    static int iterate_done(copybit_region_t const *, copybit_rect_t*) {

        return 0;

    }

    mutable copybit_rect_t r;

    mutable bool firstTime;

    copybit_rect_t r;

};

static bool supportedCopybitsFormat(int format) {