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 // Various Bug Fixes: Daniel (Redge) Sperl
33 // -----------------------------------------------------------------------------
35 * @file RenderTexture.h
37 * Interface definition for class RenderTexture. A multi-format render to
40 #ifndef __RENDERTEXTURE2_HPP__
41 #define __RENDERTEXTURE2_HPP__
47 * Jan. 2005, Removed GLEW dependencies, Erik Hofman
48 * Added MacOS X support
50 #include <simgear/compiler.h>
52 #if !defined( _WIN32 ) && !defined( __APPLE__ )
53 # include <X11/Xlib.h>
71 /* The pixel format for the pbuffer is controlled by the mode string passed
72 * into the PBuffer constructor. This string can have the following attributes:
74 * To specify the pixel format, use the following syntax.
76 * <channels> must match one of the following.
78 * r - r pixel format (for float buffer).
79 * rg - rg pixel format (for float buffer).
80 * rgb - rgb pixel format. 8 bit or 16/32 bit in float buffer mode
81 * rgba - same as "rgb alpha" string
83 * <bits> can either be a scalar--meaning the same bit depth for each
84 * channel-- or a 2-, 3-, 4-component vector matching the specified number of
85 * channels. Vector components should be comma separated. An optional 'f'
86 * suffix on the bit depth specifies float components. In this case <bits>
87 * must be either "32f" or "16f". If <bits> is empty, the default 8 bits per
88 * channel will be used.
94 * The following other attributes are supported.
96 * depth=n - must have n-bit depth buffer, omit n for default (24 bits)
97 * stencil=n - must have n-bit stencil buffer, omit n for default (8 bits)
98 * samples=n - must support n-sample antialiasing (n can be 2 or 4)
99 * aux=n - must have n AUX buffers
100 * doublebuffer - must support double buffered rendering
104 * texCUBE - must support binding pbuffer as texture to specified target
105 * - binding the depth buffer is also supported by specifying
109 * - Both depth and color texture binding, may be specified, but
110 * the targets must match!
111 * For example: "tex2D depthTex2D" or "texRECT depthTexRECT"
114 * ctt - These mutually exclusive options specify the update method used
115 * for render textures that support texture binding. "rtt"
116 * indicates that render to texture will be used to update the
117 * texture. "ctt" indicates that copy to texture will be used
118 * (i.e. glCopyTexSubImage2D()). "rtt" is the default if neither is
119 * specified, and one of the "tex*" options above is.
122 *---------------------------------------------------------------------------
126 * * Texture Parameters:
127 * The default texture wrap mode is GL_CLAMP_TO_EDGE for all textures, and
128 * the default texture filtering modes (min and mag) are GL_NEAREST.
129 * To change these parameters, simply bind the RenderTexture (using the
130 * Bind() method), and set them the way you would for any GL texture object.
131 * The same goes for depth textures.
133 * * Enabling Mipmapping:
134 * This is similar to the texture parameters above. When "rtt" is specified
135 * in the mode string, "mipmap" must also be specified in order to enable
136 * a mipmapped pbuffer. Then, the mipmaps must be created by enabling the
137 * GL_SGIS_GENERATE_MIPMAP texture parameter in the same way as above, and
138 * the min filter mode must be set to a mipmap filter mode, as with any
139 * mipmapped texture object.
141 * * Enabling Anisotropic Filtering
142 * As with the texture parameters above, except as in the following code:
143 * glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, max);
144 * glTexParameterf(target, GL_TEXTURE_MAX_ANISOTROPY_EXT, <value < max>);
151 RT_RENDER_TO_TEXTURE,
157 RenderTexture(const char *strMode="rgb tex2D");
160 //! Call this once before use. Set bShare to true to share lists, textures,
161 //! and program objects between the render texture context and the
162 //! current active GL context.
163 bool Initialize(int width, int height,
164 bool shareObjects=true,
165 bool copyContext=false);
167 // !Change the render texture format.
168 bool Reset(const char* strMode,...);
169 // !Change the size of the render texture.
170 bool Resize(int width, int height);
172 // !Begin drawing to the texture. (i.e. use as "output" texture)
174 // !Ends drawing to 'current', begins drawing to this RenderTexture
175 bool BeginCapture(RenderTexture* current);
176 // !End drawing to the texture.
179 // !Bind the texture to the active texture unit for use as an "input" texture
182 // !Bind the depth texture to the active texture unit for use as an "input" texture
183 void BindDepth() const;
185 // !Associate the RTT texture with 'iBuffer' (default is WGL_FRONT_LEFT_ARB)
186 bool BindBuffer( int iBuffer );
188 //! Enables the texture target appropriate for this render texture.
189 void EnableTextureTarget() const
190 { if (_bInitialized) glEnable(_iTextureTarget); }
191 //! Disables the texture target appropriate for this render texture.
192 void DisableTextureTarget() const
193 { if (_bInitialized) glDisable(_iTextureTarget); }
195 //! Returns the texture ID. Useful in Cg applications.
196 unsigned int GetTextureID() const { return _iTextureID; }
197 //! Returns the depth texture ID. Useful in Cg applications.
198 unsigned int GetDepthTextureID() const { return _iDepthTextureID; }
199 //! Returns the texture target this texture is bound to.
200 unsigned int GetTextureTarget() const { return _iTextureTarget; }
201 //! Conversion operator allows RenderTexture to be passed to GL calls
202 operator unsigned int()const{return _iTextureID;}
204 //! Returns the width of the offscreen buffer.
205 int GetWidth() const { return _iWidth; }
206 //! Returns the width of the offscreen buffer.
207 int GetHeight() const { return _iHeight; }
208 //! Returns the maximum S texture coordinate.
209 int GetMaxS() const { return IsRectangleTexture() ? _iWidth : 1; }
210 //! Returns the maximum T texture coordinate.
211 int GetMaxT() const { return IsRectangleTexture() ? _iHeight : 1; }
213 //! Returns the number of red bits allocated.
214 int GetRedBits() const { return _iNumColorBits[0]; }
215 //! Returns the number of green bits allocated.
216 int GetGreenBits() const { return _iNumColorBits[1]; }
217 //! Returns the number of blue bits allocated.
218 int GetBlueBits() const { return _iNumColorBits[2]; }
219 //! Returns the number of alpha bits allocated.
220 int GetAlphaBits() const { return _iNumColorBits[3]; }
222 //! Returns the number of depth bits allocated.
223 int GetDepthBits() const { return _iNumDepthBits; }
224 //! Returns the number of stencil bits allocated.
225 int GetStencilBits() const { return _iNumStencilBits; }
227 //! True if this RenderTexture has been properly initialized.
228 bool IsInitialized() const { return _bInitialized; }
229 //! True if this is a texture and not just an offscreen buffer.
230 bool IsTexture() const { return _bIsTexture; }
231 //! True if this is a depth texture and not just an offscreen buffer.
232 bool IsDepthTexture() const { return _bIsDepthTexture; }
233 //! True if this is a floating point buffer / texture.
234 bool IsFloatTexture() const { return _bFloat; }
235 //! True if this is a double-buffered pbuffer
236 bool IsDoubleBuffered() const { return _bDoubleBuffered; }
237 //! True if this texture has non-power-of-two dimensions.
238 bool IsRectangleTexture() const { return _bRectangle; }
239 //! True if this texture has non-power-of-two dimensions.
240 //! True if this pbuffer has a depth buffer.
241 bool HasDepth() const { return (_iNumDepthBits > 0); }
242 //! True if this pbuffer has a stencil buffer.
243 bool HasStencil() const { return (_iNumStencilBits > 0); }
244 //! True if this texture has mipmaps.
245 bool IsMipmapped() const { return _bMipmap; }
248 * @fn IsPowerOfTwo(int n)
249 * @brief Returns true if /param n is an integer power of 2.
251 * Taken from Steve Baker's Cute Code Collection.
252 * http://www.sjbaker.org/steve/software/cute_code.html
254 static bool IsPowerOfTwo(int n) { return ((n&(n-1))==0); }
257 /////////////////////////////////////////////////////////////////////////
258 // This is the deprecated (old) interface. It will likely be removed
259 // in a future version, so it is recommended that you transition to the
260 // new mode-string-based interface.
261 RenderTexture(int width, int height,
262 bool bIsTexture = true,
263 bool bIsDepthTexture = false);
265 // Call this once before use. Set bShare to true to share lists,
266 // textures, and program objects between the render texture context
267 // and the current active GL context. [deprecated]
268 bool Initialize(bool bShare = true,
270 bool bStencil = false,
271 bool bMipmap = false,
272 bool bAnisoFilter = false,
273 unsigned int iRBits = 8,
274 unsigned int iGBits = 8,
275 unsigned int iBBits = 8,
276 unsigned int iABits = 8,
277 // Only Win32 has RT now, so only make it default there
279 UpdateMode updateMode = RT_RENDER_TO_TEXTURE
281 UpdateMode updateMode = RT_COPY_TO_TEXTURE
284 // !Change the render texture resolution. [deprecated]
285 bool Reset(int iWidth, int iHeight);
287 /////////////////////////////////////////////////////////////////////////
290 protected: // methods
293 typedef std::pair<std::string, std::string> KeyVal;
295 void _ParseModeString(const char *modeString,
296 std::vector<int> &pixelFormatAttribs,
297 std::vector<int> &pbufferAttribs);
299 std::vector<int> _ParseBitVector(std::string bitVector);
300 KeyVal _GetKeyValuePair(std::string token);
303 bool _VerifyExtensions();
304 bool _InitializeTextures();
306 void _MaybeCopyBuffer();
307 bool _ReleaseBoundBuffers();
309 bool _BindDepthBuffer( ) const;
312 int _iWidth; // width of the pbuffer
313 int _iHeight; // height of the pbuffer
316 bool _bIsDepthTexture;
317 bool _bHasARBDepthTexture; // [Redge]
319 UpdateMode _eUpdateMode;
323 unsigned int _iNumAuxBuffers;
324 bool _bIsBufferBound;
325 int _iCurrentBoundBuffer;
327 unsigned int _iNumComponents;
328 unsigned int _iNumColorBits[4];
329 unsigned int _iNumDepthBits;
330 unsigned int _iNumStencilBits;
334 bool _bDoubleBuffered;
343 HDC _hDC; // Handle to a device context.
344 HGLRC _hGLContext; // Handle to a GL context.
345 HPBUFFERARB _hPBuffer; // Handle to a pbuffer.
348 HGLRC _hPreviousContext;
349 #elif defined( __APPLE__ )
353 GLXContext _hGLContext;
354 GLXPbuffer _hPBuffer;
356 GLXDrawable _hPreviousDrawable;
357 GLXContext _hPreviousContext;
361 GLenum _iTextureTarget;
362 unsigned int _iTextureID;
363 unsigned int _iDepthTextureID;
365 unsigned short* _pPoorDepthTexture; // [Redge]
367 std::vector<int> _pixelFormatAttribs;
368 std::vector<int> _pbufferAttribs;
371 // Using these could lead to some odd behavior
372 RenderTexture(const RenderTexture&);
373 RenderTexture& operator=(const RenderTexture&);
376 #endif //__RENDERTEXTURE2_HPP__