63 lines
1.3 KiB
C++
63 lines
1.3 KiB
C++
/*
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* \brief Texture with backing store for pixels and alpha channel
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* \author Norman Feske
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* \date 2014-08-22
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*/
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/*
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* Copyright (C) 2014 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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#ifndef _INCLUDE__GEMS__CHUNKY_TEXTURE_H_
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#define _INCLUDE__GEMS__CHUNKY_TEXTURE_H_
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#include <os/surface.h>
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#include <os/attached_ram_dataspace.h>
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template <typename PT>
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class Chunky_texture : Genode::Attached_ram_dataspace, public Genode::Texture<PT>
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{
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private:
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typedef Genode::Surface_base::Area Area;
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/**
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* Calculate memory needed to store the texture
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*/
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static Genode::size_t _num_bytes(Area size)
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{
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/* account for pixel size + 1 byte per alpha value */
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return size.count()*(sizeof(PT) + 1);
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}
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/**
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* Return base of pixel buffer
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*/
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PT *_pixel()
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{
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return local_addr<PT>();
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}
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/**
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* Return base of alpha buffer
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*/
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unsigned char *_alpha(Area size)
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{
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/* alpha buffer follows pixel buffer */
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return (unsigned char *)(local_addr<PT>() + size.count());
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}
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public:
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Chunky_texture(Genode::Ram_session &ram, Genode::Surface_base::Area size)
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:
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Genode::Attached_ram_dataspace(&ram, _num_bytes(size)),
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Genode::Texture<PT>(_pixel(), _alpha(size), size)
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{ }
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};
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#endif /* _INCLUDE__GEMS__CHUNKY_TEXTURE_H_ */
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