xrb_rendercontext.hpp

// ///////////////////////////////////////////////////////////////////////////
// xrb_rendercontext.hpp by Victor Dods, created 2005/02/07
// ///////////////////////////////////////////////////////////////////////////
// Unless a different license was explicitly granted in writing by the
// copyright holder (Victor Dods), this software is freely distributable under
// the terms of the GNU General Public License, version 2.  Any works deriving
// from this work must also be released under the GNU GPL.  See the included
// file LICENSE for details.
// ///////////////////////////////////////////////////////////////////////////

#if !defined(_XRB_RENDERCONTEXT_HPP_)
#define _XRB_RENDERCONTEXT_HPP_

#include "xrb.hpp"

#include "xrb_color.hpp"
#include "xrb_screencoord.hpp"

namespace Xrb
{

class RenderContext
{
public:

    inline RenderContext (
        ScreenCoordRect const &clip_rect,
        Color const &color_bias,
        Color const &color_mask)
        :
        m_clip_rect(clip_rect),
        m_color_bias(color_bias),
        m_color_mask(color_mask)
    { }
    inline RenderContext (RenderContext const &source)
        :
        m_clip_rect(source.m_clip_rect),
        m_color_bias(source.m_color_bias),
        m_color_mask(source.m_color_mask)
    { }
    inline ~RenderContext () { }

    inline void operator = (RenderContext const &source)
    {
        m_clip_rect = source.m_clip_rect;
        m_color_bias = source.m_color_bias;
        m_color_mask = source.m_color_mask;
    }

    inline ScreenCoordRect const &ClipRect () const
    {
        return m_clip_rect;
    }
    inline Color const &ColorBias () const
    {
        return m_color_bias;
    }
    inline Color const &ColorMask () const
    {
        return m_color_mask;
    }
    inline Color &ColorBias ()
    {
        return m_color_bias;
    }
    inline Color &ColorMask ()
    {
        return m_color_mask;
    }
    inline ScreenCoordRect ClippedRect (ScreenCoordRect const &rect) const
    {
        return m_clip_rect & rect;
    }
    inline Color BlendedColorBias (Color const &color_bias) const
    {
        Color blended_color_bias(m_color_bias);
        blended_color_bias.Blend(color_bias);
        return blended_color_bias;
    }
    inline Color MaskedColor (Color const &color) const
    {
        return m_color_mask * color;
    }
    bool MaskAndBiasWouldResultInNoOp () const;
    bool MaskAndBiasWouldResultInNoOp (ColorCoord color_alpha_channel_value) const;

    inline void SetClipRect (ScreenCoordRect const &clip_rect)
    {
        m_clip_rect = clip_rect;
    }

    inline void ApplyClipRect (ScreenCoordRect const &clip_rect)
    {
        m_clip_rect &= clip_rect;
    }
    inline void ApplyColorBias (Color const &color_bias)
    {
        m_color_bias.Blend(color_bias);
    }
    inline void ApplyColorMask (Color const &color_mask)
    {
        m_color_mask *= color_mask;
    }
    inline void ApplyAlphaMaskToColorMask (Float const alpha_mask)
    {
        m_color_mask[Dim::A] *= alpha_mask;
    }
    void SetupGLClipRect () const;

private:

    ScreenCoordRect m_clip_rect;
    Color m_color_bias;
    Color m_color_mask;
}; // end of class RenderContext

} // end of namespace Xrb

#endif // !defined(_XRB_RENDERCONTEXT_HPP_)

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