canvas/inc/rendering/irendermodule.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <memory>
  23
  24 namespace basegfx
  25 {
  26     class B2IVector;
  27 }
  28
  29 namespace canvas
  30 {
  31     struct ISurface;
  32
  33     struct Vertex
  34     {
  35         float r,g,b,a;
  36         float u,v;
  37         float x,y,z;
  38     };
  39
  40     /** Output module interface for backend render implementations.
  41
  42         Implement this interface for each operating system- or
  43         library-specific rendering backend, which needs coupling with
  44         the canvas rendering framework (which can be shared between
  45         all backend implementations).
  46      */
  47     struct IRenderModule
  48     {
  49         /** Type of primitive passed to the render module via
  50             pushVertex()
  51          */
  52         enum class PrimitiveType
  53         {
  54             Unknown,
  55             Triangle,
  56             Quad
  57         };
  58
  59         virtual ~IRenderModule() {}
  60
  61         /// Lock rendermodule against concurrent access
  62         virtual void lock() const = 0;
  63
  64         /// Unlock rendermodule for concurrent access
  65         virtual void unlock() const = 0;
  66
  67         /** Maximal size of VRAM pages available
  68
  69             This is typically the maximum texture size of the
  70             hardware, or some arbitrary limit if the backend is
  71             software.
  72          */
  73         virtual ::basegfx::B2IVector getPageSize() = 0;
  74
  75         /** Create a (possibly hardware-accelerated) surface
  76
  77             @return a pointer to a surface, which is an abstraction of
  78             a piece of (possibly hardware-accelerated) texture memory.
  79          */
  80         virtual std::shared_ptr<ISurface> createSurface( const ::basegfx::B2IVector& surfaceSize ) = 0;
  81
  82         /** Begin rendering the given primitive.
  83
  84             Each beginPrimitive() call must be matched with an
  85             endPrimitive() call.
  86          */
  87         virtual void      beginPrimitive( PrimitiveType eType ) = 0;
  88
  89         /** Finish rendering a primitive.
  90
  91             Each beginPrimitive() call must be matched with an
  92             endPrimitive() call.
  93          */
  94         virtual void      endPrimitive() = 0;
  95
  96         /** Add given vertex to current primitive
  97
  98             After issuing a beginPrimitive(), each pushVertex() adds a
  99             vertex to the active primitive.
 100          */
 101         virtual void      pushVertex( const Vertex& vertex ) = 0;
 102
 103         /** Query error status
 104
 105             @returns true, if an error occurred during primitive
 106             construction.
 107          */
 108         virtual bool      isError() = 0;
 109     };
 110
 111     /// Little RAII wrapper for guarding access to IRenderModule interface
 112     class RenderModuleGuard
 113     {
 114     public:
 115         explicit RenderModuleGuard( const std::shared_ptr<IRenderModule>& rRenderModule ) :
 116             mpRenderModule( rRenderModule )
 117         {
 118             mpRenderModule->lock();
 119         }
 120
 121         ~RenderModuleGuard()
 122         {
 123             mpRenderModule->unlock();
 124         }
 125
 126         RenderModuleGuard(const RenderModuleGuard&) = delete;
 127         RenderModuleGuard& operator=( const RenderModuleGuard& ) = delete;
 128     private:
 129         const std::shared_ptr<IRenderModule> mpRenderModule;
 130     };
 131 }
 132
 133 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */