1 /*
2   -----------------------------------------------------------------------------
3   This source file is part of OGRE
4   (Object-oriented Graphics Rendering Engine)
5   For the latest info, see http://www.ogre3d.org/
6 
7 Copyright (c) 2000-2014 Torus Knot Software Ltd
8 
9   Permission is hereby granted, free of charge, to any person obtaining a copy
10   of this software and associated documentation files (the "Software"), to deal
11   in the Software without restriction, including without limitation the rights
12   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13   copies of the Software, and to permit persons to whom the Software is
14   furnished to do so, subject to the following conditions:
15 
16   The above copyright notice and this permission notice shall be included in
17   all copies or substantial portions of the Software.
18 
19   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25   THE SOFTWARE.
26   -----------------------------------------------------------------------------
27 */
28 #ifndef __RenderToVertexBuffer_H__
29 #define __RenderToVertexBuffer_H__
30 
31 #include "OgrePrerequisites.h"
32 #include "OgreRenderOperation.h"
33 #include "OgreHeaderPrefix.h"
34 
35 namespace Ogre {
36     /** \addtogroup Core
37      *  @{
38      */
39     /** \addtogroup RenderSystem
40      *  @{
41      */
42     /**
43        An object which renders geometry to a vertex.
44        @remarks
45        This is especially useful together with geometry shaders, as you can
46        render procedural geometry which will get saved to a vertex buffer for
47        reuse later, without regenerating it again. You can also create shaders
48        that run on previous results of those shaders, creating stateful
49        shaders.
50     */
51     class _OgreExport RenderToVertexBuffer
52     {
53     public:
54         RenderToVertexBuffer();
55         virtual ~RenderToVertexBuffer();
56 
57         /**
58            Get the vertex declaration that the pass will output.
59            @remarks
60            Use this object to set the elements of the buffer. Object will calculate
61            buffers on its own. Only one source allowed!
62         */
63         VertexDeclaration* getVertexDeclaration();
64 
65         /**
66            Get the maximum number of vertices that the buffer will hold
67         */
getMaxVertexCount()68         unsigned int getMaxVertexCount() const { return mMaxVertexCount; }
69 
70         /**
71            Set the maximum number of vertices that the buffer will hold
72         */
setMaxVertexCount(unsigned int maxVertexCount)73         void setMaxVertexCount(unsigned int maxVertexCount) { mMaxVertexCount = maxVertexCount; }
74 
75         /**
76            What type of primitives does this object generate?
77         */
getOperationType()78         RenderOperation::OperationType getOperationType() const { return mOperationType; }
79 
80         /**
81            Set the type of primitives that this object generates
82         */
setOperationType(RenderOperation::OperationType operationType)83         void setOperationType(RenderOperation::OperationType operationType) { mOperationType = operationType; }
84 
85         /**
86            Set whether this object resets its buffers each time it updates.
87         */
setResetsEveryUpdate(bool resetsEveryUpdate)88         void setResetsEveryUpdate(bool resetsEveryUpdate) { mResetsEveryUpdate = resetsEveryUpdate; }
89 
90         /**
91            Does this object reset its buffer each time it updates?
92         */
getResetsEveryUpdate()93         bool getResetsEveryUpdate() const { return mResetsEveryUpdate; }
94 
95         /**
96            Get the render operation for this buffer
97         */
98         virtual void getRenderOperation(RenderOperation& op) = 0;
99 
100         /**
101            Update the contents of this vertex buffer by rendering
102         */
103         virtual void update(SceneManager* sceneMgr) = 0;
104 
105         /**
106            Reset the vertex buffer to the initial state. In the next update,
107            the source renderable will be used as input.
108         */
reset()109         virtual void reset() { mResetRequested = true; }
110 
111         /**
112            Set the source renderable of this object. During the first (and
113            perhaps later) update of this object, this object's data will be
114            used as input)
115         */
setSourceRenderable(Renderable * source)116         void setSourceRenderable(Renderable* source) { mSourceRenderable = source; }
117 
118         /**
119            Get the source renderable of this object
120         */
getSourceRenderable()121         const Renderable* getSourceRenderable() const { return mSourceRenderable; }
122 
123         /**
124            Get the material which is used to render the geometry into the
125            vertex buffer.
126         */
getRenderToBufferMaterial()127         const MaterialPtr& getRenderToBufferMaterial() { return mMaterial; }
128 
129         /**
130            Set the material name which is used to render the geometry into
131            the vertex buffer
132         */
133         void setRenderToBufferMaterialName(const String& materialName);
134 
135     protected:
136         RenderOperation::OperationType mOperationType;
137         bool mResetsEveryUpdate;
138         bool mResetRequested;
139         MaterialPtr mMaterial;
140         Renderable* mSourceRenderable;
141         std::unique_ptr<VertexData> mVertexData;
142         unsigned int mMaxVertexCount;
143     };
144 
145     /** @} */
146     /** @} */
147 }
148 
149 #include "OgreHeaderSuffix.h"
150 
151 #endif
152