1 //------------------------------------------------------------------------------
2 // File : RenderTexture.h
3 //------------------------------------------------------------------------------
4 // Copyright (c) 2002-2004 Mark J. Harris
5 //---------------------------------------------------------------------------
6 // This software is provided 'as-is', without any express or implied
7 // warranty. In no event will the authors be held liable for any
8 // damages arising from the use of this software.
10 // Permission is granted to anyone to use this software for any
11 // purpose, including commercial applications, and to alter it and
12 // redistribute it freely, subject to the following restrictions:
14 // 1. The origin of this software must not be misrepresented; you
15 // must not claim that you wrote the original software. If you use
16 // this software in a product, an acknowledgment in the product
17 // documentation would be appreciated but is not required.
19 // 2. Altered source versions must be plainly marked as such, and
20 // must not be misrepresented as being the original software.
22 // 3. This notice may not be removed or altered from any source
25 // -----------------------------------------------------------------------------
27 // Original RenderTexture code: Mark J. Harris
28 // Original Render-to-depth-texture support: Thorsten Scheuermann
29 // Linux Copy-to-texture: Eric Werness
30 // OS X: Alexander Powell (someone please help)
31 // Various Bug Fixes: Daniel (Redge) Sperl
34 // -----------------------------------------------------------------------------
36 * @file RenderTexture.h
38 * Interface definition for class RenderTexture. A multi-format render to
41 #ifndef __RENDERTEXTURE2_HPP__
42 #define __RENDERTEXTURE2_HPP__
48 * Jan. 2005, Removed GLEW dependencies, Erik Hofman
49 * Mar. 2006, Added MAC OS X support, Alexander Powell
51 #include <simgear/compiler.h>
53 #if !defined( _WIN32 ) && !defined( __MACH__ )
54 # include <X11/Xlib.h>
64 /* The pixel format for the pbuffer is controlled by the mode string passed
65 * into the PBuffer constructor. This string can have the following attributes:
67 * To specify the pixel format, use the following syntax.
69 * <channels> must match one of the following.
71 * r - r pixel format (for float buffer).
72 * rg - rg pixel format (for float buffer).
73 * rgb - rgb pixel format. 8 bit or 16/32 bit in float buffer mode
74 * rgba - same as "rgb alpha" string
76 * <bits> can either be a scalar--meaning the same bit depth for each
77 * channel-- or a 2-, 3-, 4-component vector matching the specified number of
78 * channels. Vector components should be comma separated. An optional 'f'
79 * suffix on the bit depth specifies float components. In this case <bits>
80 * must be either "32f" or "16f". If <bits> is empty, the default 8 bits per
81 * channel will be used.
87 * The following other attributes are supported.
89 * depth=n - must have n-bit depth buffer, omit n for default (24 bits)
90 * stencil=n - must have n-bit stencil buffer, omit n for default (8 bits)
91 * samples=n - must support n-sample antialiasing (n can be 2 or 4)
92 * aux=n - must have n AUX buffers
93 * doublebuffer - must support double buffered rendering
97 * texCUBE - must support binding pbuffer as texture to specified target
98 * - binding the depth buffer is also supported by specifying
102 * - Both depth and color texture binding, may be specified, but
103 * the targets must match!
104 * For example: "tex2D depthTex2D" or "texRECT depthTexRECT"
107 * ctt - These mutually exclusive options specify the update method used
108 * for render textures that support texture binding. "rtt"
109 * indicates that render to texture will be used to update the
110 * texture. "ctt" indicates that copy to texture will be used
111 * (i.e. glCopyTexSubImage2D()). "rtt" is the default if neither is
112 * specified, and one of the "tex*" options above is.
115 *---------------------------------------------------------------------------
119 * * Texture Parameters:
120 * The default texture wrap mode is GL_CLAMP_TO_EDGE for all textures, and
121 * the default texture filtering modes (min and mag) are GL_NEAREST.
122 * To change these parameters, simply bind the RenderTexture (using the
123 * Bind() method), and set them the way you would for any GL texture object.
124 * The same goes for depth textures.
126 * * Enabling Mipmapping:
127 * This is similar to the texture parameters above. When "rtt" is specified
128 * in the mode string, "mipmap" must also be specified in order to enable
129 * a mipmapped pbuffer. Then, the mipmaps must be created by enabling the
130 * GL_SGIS_GENERATE_MIPMAP texture parameter in the same way as above, and
131 * the min filter mode must be set to a mipmap filter mode, as with any
132 * mipmapped texture object.
134 * * Enabling Anisotropic Filtering
135 * As with the texture parameters above, except as in the following code:
136 * glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, max);
137 * glTexParameterf(target, GL_TEXTURE_MAX_ANISOTROPY_EXT, <value < max>);
144 RT_RENDER_TO_TEXTURE,
150 RenderTexture(const char *strMode="rgb tex2D");
153 //! Call this once before use. Set bShare to true to share lists, textures,
154 //! and program objects between the render texture context and the
155 //! current active GL context.
156 bool Initialize(int width, int height,
157 bool shareObjects=true,
158 bool copyContext=false);
160 // !Change the render texture format.
161 bool Reset(const char* strMode,...);
162 // !Change the size of the render texture.
163 bool Resize(int width, int height);
165 // !Begin drawing to the texture. (i.e. use as "output" texture)
167 // !Ends drawing to 'current', begins drawing to this RenderTexture
168 bool BeginCapture(RenderTexture* current);
169 // !End drawing to the texture.
172 // !Bind the texture to the active texture unit for use as an "input" texture
175 // !Bind the depth texture to the active texture unit for use as an "input" texture
176 void BindDepth() const;
178 // !Associate the RTT texture with 'iBuffer' (default is WGL_FRONT_LEFT_ARB)
179 bool BindBuffer( int iBuffer );
181 //! Enables the texture target appropriate for this render texture.
182 void EnableTextureTarget() const
183 { if (_bInitialized) glEnable(_iTextureTarget); }
184 //! Disables the texture target appropriate for this render texture.
185 void DisableTextureTarget() const
186 { if (_bInitialized) glDisable(_iTextureTarget); }
188 //! Returns the texture ID. Useful in Cg applications.
189 unsigned int GetTextureID() const { return _iTextureID; }
190 //! Returns the depth texture ID. Useful in Cg applications.
191 unsigned int GetDepthTextureID() const { return _iDepthTextureID; }
192 //! Returns the texture target this texture is bound to.
193 unsigned int GetTextureTarget() const { return _iTextureTarget; }
194 //! Conversion operator allows RenderTexture to be passed to GL calls
195 operator unsigned int()const{return _iTextureID;}
197 //! Returns the width of the offscreen buffer.
198 int GetWidth() const { return _iWidth; }
199 //! Returns the width of the offscreen buffer.
200 int GetHeight() const { return _iHeight; }
201 //! Returns the maximum S texture coordinate.
202 int GetMaxS() const { return IsRectangleTexture() ? _iWidth : 1; }
203 //! Returns the maximum T texture coordinate.
204 int GetMaxT() const { return IsRectangleTexture() ? _iHeight : 1; }
206 //! Returns the number of red bits allocated.
207 int GetRedBits() const { return _iNumColorBits[0]; }
208 //! Returns the number of green bits allocated.
209 int GetGreenBits() const { return _iNumColorBits[1]; }
210 //! Returns the number of blue bits allocated.
211 int GetBlueBits() const { return _iNumColorBits[2]; }
212 //! Returns the number of alpha bits allocated.
213 int GetAlphaBits() const { return _iNumColorBits[3]; }
215 //! Returns the number of depth bits allocated.
216 int GetDepthBits() const { return _iNumDepthBits; }
217 //! Returns the number of stencil bits allocated.
218 int GetStencilBits() const { return _iNumStencilBits; }
220 //! True if this RenderTexture has been properly initialized.
221 bool IsInitialized() const { return _bInitialized; }
222 //! True if this is a texture and not just an offscreen buffer.
223 bool IsTexture() const { return _bIsTexture; }
224 //! True if this is a depth texture and not just an offscreen buffer.
225 bool IsDepthTexture() const { return _bIsDepthTexture; }
226 //! True if this is a floating point buffer / texture.
227 bool IsFloatTexture() const { return _bFloat; }
228 //! True if this is a double-buffered pbuffer
229 bool IsDoubleBuffered() const { return _bDoubleBuffered; }
230 //! True if this texture has non-power-of-two dimensions.
231 bool IsRectangleTexture() const { return _bRectangle; }
232 //! True if this texture has non-power-of-two dimensions.
233 //! True if this pbuffer has a depth buffer.
234 bool HasDepth() const { return (_iNumDepthBits > 0); }
235 //! True if this pbuffer has a stencil buffer.
236 bool HasStencil() const { return (_iNumStencilBits > 0); }
237 //! True if this texture has mipmaps.
238 bool IsMipmapped() const { return _bMipmap; }
241 * @fn IsPowerOfTwo(int n)
242 * @brief Returns true if /param n is an integer power of 2.
244 * Taken from Steve Baker's Cute Code Collection.
245 * http://www.sjbaker.org/steve/software/cute_code.html
247 static bool IsPowerOfTwo(int n) { return ((n&(n-1))==0); }
250 /////////////////////////////////////////////////////////////////////////
251 // This is the deprecated (old) interface. It will likely be removed
252 // in a future version, so it is recommended that you transition to the
253 // new mode-string-based interface.
254 RenderTexture(int width, int height,
255 bool bIsTexture = true,
256 bool bIsDepthTexture = false);
258 // Call this once before use. Set bShare to true to share lists,
259 // textures, and program objects between the render texture context
260 // and the current active GL context. [deprecated]
261 bool Initialize(bool bShare = true,
263 bool bStencil = false,
264 bool bMipmap = false,
265 bool bAnisoFilter = false,
266 unsigned int iRBits = 8,
267 unsigned int iGBits = 8,
268 unsigned int iBBits = 8,
269 unsigned int iABits = 8,
270 // Only Win32 has RT now, so only make it default there
272 UpdateMode updateMode = RT_RENDER_TO_TEXTURE
274 UpdateMode updateMode = RT_COPY_TO_TEXTURE
277 // !Change the render texture resolution. [deprecated]
278 bool Reset(int iWidth, int iHeight);
280 /////////////////////////////////////////////////////////////////////////
283 protected: // methods
286 typedef std::pair<std::string, std::string> KeyVal;
288 void _ParseModeString(const char *modeString,
289 std::vector<int> &pixelFormatAttribs,
290 std::vector<int> &pbufferAttribs);
292 std::vector<int> _ParseBitVector(std::string bitVector);
293 KeyVal _GetKeyValuePair(std::string token);
296 bool _VerifyExtensions();
297 bool _InitializeTextures();
299 void _MaybeCopyBuffer();
300 bool _ReleaseBoundBuffers();
302 bool _BindDepthBuffer( ) const;
305 int _iWidth; // width of the pbuffer
306 int _iHeight; // height of the pbuffer
309 bool _bIsDepthTexture;
310 bool _bHasARBDepthTexture; // [Redge]
312 UpdateMode _eUpdateMode;
316 unsigned int _iNumAuxBuffers;
317 bool _bIsBufferBound;
318 int _iCurrentBoundBuffer;
320 unsigned int _iNumComponents;
321 unsigned int _iNumColorBits[4];
322 unsigned int _iNumDepthBits;
323 unsigned int _iNumStencilBits;
327 bool _bDoubleBuffered;
336 HDC _hDC; // Handle to a device context.
337 HGLRC _hGLContext; // Handle to a GL context.
338 HPBUFFERARB _hPBuffer; // Handle to a pbuffer.
341 HGLRC _hPreviousContext;
342 #elif defined( __MACH__ )
343 CGLContextObj _hGLContext;
344 CGLPBufferObj _hPBuffer;
346 CGLContextObj _hPreviousContext;
349 GLXContext _hGLContext;
350 GLXPbuffer _hPBuffer;
352 GLXDrawable _hPreviousDrawable;
353 GLXContext _hPreviousContext;
357 GLenum _iTextureTarget;
359 GLuint _iDepthTextureID;
361 unsigned short* _pPoorDepthTexture; // [Redge]
363 std::vector<int> _pixelFormatAttribs;
364 std::vector<int> _pbufferAttribs;
367 // Using these could lead to some odd behavior
368 RenderTexture(const RenderTexture&);
369 RenderTexture& operator=(const RenderTexture&);
372 #endif //__RENDERTEXTURE2_HPP__