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) 2008 Renato Araujo Oliveira Filho <renatox@gmail.com>
8 Copyright (c) 2000-2013 Torus Knot Software Ltd
9 
10 Permission is hereby granted, free of charge, to any person obtaining a copy
11 of this software and associated documentation files (the "Software"), to deal
12 in the Software without restriction, including without limitation the rights
13 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 copies of the Software, and to permit persons to whom the Software is
15 furnished to do so, subject to the following conditions:
16 
17 The above copyright notice and this permission notice shall be included in
18 all copies or substantial portions of the Software.
19 
20 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 THE SOFTWARE.
27 -----------------------------------------------------------------------------
28 */
29 
30 #ifndef __GLESPixelFormat_H__
31 #define __GLESPixelFormat_H__
32 
33 #include "OgreGLESPrerequisites.h"
34 #include "OgrePixelFormat.h"
35 
36 namespace Ogre {
37     /**
38     * Class to do pixel format mapping between GL and OGRE
39     */
40     class _OgreGLESExport GLESPixelUtil
41     {
42         public:
43             /** Takes the OGRE pixel format and returns the appropriate GL one
44                 @returns a GLenum describing the format, or 0 if there is no exactly matching
45                 one (and conversion is needed)
46             */
47             static GLenum getGLOriginFormat(PixelFormat mFormat);
48 
49             /** Takes the OGRE pixel format and returns type that must be provided
50                 to GL as data type for reading it into the GPU
51                 @returns a GLenum describing the data type, or 0 if there is no exactly matching
52                 one (and conversion is needed)
53             */
54             static GLenum getGLOriginDataType(PixelFormat mFormat);
55 
56             /**    Takes the OGRE pixel format and returns the type that must be provided
57                 to GL as internal format. GL_NONE if no match exists.
58             @param mFormat The pixel format
59             @param hwGamma Whether a hardware gamma-corrected version is requested
60             */
61             static GLenum getGLInternalFormat(PixelFormat mFormat, bool hwGamma = false);
62 
63             /**    Takes the OGRE pixel format and returns the type that must be provided
64                 to GL as internal format. If no match exists, returns the closest match.
65             @param mFormat The pixel format
66             @param hwGamma Whether a hardware gamma-corrected version is requested
67             */
68             static GLenum getClosestGLInternalFormat(PixelFormat mFormat, bool hwGamma = false);
69 
70             /**    Function to get the closest matching OGRE format to an internal GL format. To be
71                 precise, the format will be chosen that is most efficient to transfer to the card
72                 without losing precision.
73                 @remarks It is valid for this function to always return PF_A8R8G8B8.
74             */
75             static PixelFormat getClosestOGREFormat(GLenum fmt, GLenum dataType);
76 
77             /** Returns the maximum number of Mipmaps that can be generated until we reach
78                 the mininum format possible. This does not count the base level.
79                 @param width
80                     The width of the area
81                 @param height
82                     The height of the area
83                 @param depth
84                     The depth of the area
85                 @param format
86                     The format of the area
87                 @remarks
88                     In case that the format is non-compressed, this simply returns
89                     how many times we can divide this texture in 2 until we reach 1x1.
90                     For compressed formats, constraints apply on minimum size and alignment
91                     so this might differ.
92             */
93             static size_t getMaxMipmaps(size_t width, size_t height, size_t depth, PixelFormat format);
94 
95             /** Returns next power-of-two size if required by render system, in case
96                 RSC_NON_POWER_OF_2_TEXTURES is supported it returns value as-is.
97             */
98             static size_t optionalPO2(size_t value);
99             static void convertToGLformat(const PixelBox &src, const PixelBox &dst);
100     };
101 }
102 
103 #endif
104