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>
72 /* The pixel format for the pbuffer is controlled by the mode string passed
73 * into the PBuffer constructor. This string can have the following attributes:
75 * To specify the pixel format, use the following syntax.
77 * <channels> must match one of the following.
79 * r - r pixel format (for float buffer).
80 * rg - rg pixel format (for float buffer).
81 * rgb - rgb pixel format. 8 bit or 16/32 bit in float buffer mode
82 * rgba - same as "rgb alpha" string
84 * <bits> can either be a scalar--meaning the same bit depth for each
85 * channel-- or a 2-, 3-, 4-component vector matching the specified number of
86 * channels. Vector components should be comma separated. An optional 'f'
87 * suffix on the bit depth specifies float components. In this case <bits>
88 * must be either "32f" or "16f". If <bits> is empty, the default 8 bits per
89 * channel will be used.
95 * The following other attributes are supported.
97 * depth=n - must have n-bit depth buffer, omit n for default (24 bits)
98 * stencil=n - must have n-bit stencil buffer, omit n for default (8 bits)
99 * samples=n - must support n-sample antialiasing (n can be 2 or 4)
100 * aux=n - must have n AUX buffers
101 * doublebuffer - must support double buffered rendering
105 * texCUBE - must support binding pbuffer as texture to specified target
106 * - binding the depth buffer is also supported by specifying
110 * - Both depth and color texture binding, may be specified, but
111 * the targets must match!
112 * For example: "tex2D depthTex2D" or "texRECT depthTexRECT"
115 * ctt - These mutually exclusive options specify the update method used
116 * for render textures that support texture binding. "rtt"
117 * indicates that render to texture will be used to update the
118 * texture. "ctt" indicates that copy to texture will be used
119 * (i.e. glCopyTexSubImage2D()). "rtt" is the default if neither is
120 * specified, and one of the "tex*" options above is.
123 *---------------------------------------------------------------------------
127 * * Texture Parameters:
128 * The default texture wrap mode is GL_CLAMP_TO_EDGE for all textures, and
129 * the default texture filtering modes (min and mag) are GL_NEAREST.
130 * To change these parameters, simply bind the RenderTexture (using the
131 * Bind() method), and set them the way you would for any GL texture object.
132 * The same goes for depth textures.
134 * * Enabling Mipmapping:
135 * This is similar to the texture parameters above. When "rtt" is specified
136 * in the mode string, "mipmap" must also be specified in order to enable
137 * a mipmapped pbuffer. Then, the mipmaps must be created by enabling the
138 * GL_SGIS_GENERATE_MIPMAP texture parameter in the same way as above, and
139 * the min filter mode must be set to a mipmap filter mode, as with any
140 * mipmapped texture object.
142 * * Enabling Anisotropic Filtering
143 * As with the texture parameters above, except as in the following code:
144 * glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, max);
145 * glTexParameterf(target, GL_TEXTURE_MAX_ANISOTROPY_EXT, <value < max>);
152 RT_RENDER_TO_TEXTURE,
158 RenderTexture(const char *strMode="rgb tex2D");
161 //! Call this once before use. Set bShare to true to share lists, textures,
162 //! and program objects between the render texture context and the
163 //! current active GL context.
164 bool Initialize(int width, int height,
165 bool shareObjects=true,
166 bool copyContext=false);
168 // !Change the render texture format.
169 bool Reset(const char* strMode,...);
170 // !Change the size of the render texture.
171 bool Resize(int width, int height);
173 // !Begin drawing to the texture. (i.e. use as "output" texture)
175 // !Ends drawing to 'current', begins drawing to this RenderTexture
176 bool BeginCapture(RenderTexture* current);
177 // !End drawing to the texture.
180 // !Bind the texture to the active texture unit for use as an "input" texture
183 // !Bind the depth texture to the active texture unit for use as an "input" texture
184 void BindDepth() const;
186 // !Associate the RTT texture with 'iBuffer' (default is WGL_FRONT_LEFT_ARB)
187 bool BindBuffer( int iBuffer );
189 //! Enables the texture target appropriate for this render texture.
190 void EnableTextureTarget() const
191 { if (_bInitialized) glEnable(_iTextureTarget); }
192 //! Disables the texture target appropriate for this render texture.
193 void DisableTextureTarget() const
194 { if (_bInitialized) glDisable(_iTextureTarget); }
196 //! Returns the texture ID. Useful in Cg applications.
197 unsigned int GetTextureID() const { return _iTextureID; }
198 //! Returns the depth texture ID. Useful in Cg applications.
199 unsigned int GetDepthTextureID() const { return _iDepthTextureID; }
200 //! Returns the texture target this texture is bound to.
201 unsigned int GetTextureTarget() const { return _iTextureTarget; }
202 //! Conversion operator allows RenderTexture to be passed to GL calls
203 operator unsigned int()const{return _iTextureID;}
205 //! Returns the width of the offscreen buffer.
206 int GetWidth() const { return _iWidth; }
207 //! Returns the width of the offscreen buffer.
208 int GetHeight() const { return _iHeight; }
209 //! Returns the maximum S texture coordinate.
210 int GetMaxS() const { return IsRectangleTexture() ? _iWidth : 1; }
211 //! Returns the maximum T texture coordinate.
212 int GetMaxT() const { return IsRectangleTexture() ? _iHeight : 1; }
214 //! Returns the number of red bits allocated.
215 int GetRedBits() const { return _iNumColorBits[0]; }
216 //! Returns the number of green bits allocated.
217 int GetGreenBits() const { return _iNumColorBits[1]; }
218 //! Returns the number of blue bits allocated.
219 int GetBlueBits() const { return _iNumColorBits[2]; }
220 //! Returns the number of alpha bits allocated.
221 int GetAlphaBits() const { return _iNumColorBits[3]; }
223 //! Returns the number of depth bits allocated.
224 int GetDepthBits() const { return _iNumDepthBits; }
225 //! Returns the number of stencil bits allocated.
226 int GetStencilBits() const { return _iNumStencilBits; }
228 //! True if this RenderTexture has been properly initialized.
229 bool IsInitialized() const { return _bInitialized; }
230 //! True if this is a texture and not just an offscreen buffer.
231 bool IsTexture() const { return _bIsTexture; }
232 //! True if this is a depth texture and not just an offscreen buffer.
233 bool IsDepthTexture() const { return _bIsDepthTexture; }
234 //! True if this is a floating point buffer / texture.
235 bool IsFloatTexture() const { return _bFloat; }
236 //! True if this is a double-buffered pbuffer
237 bool IsDoubleBuffered() const { return _bDoubleBuffered; }
238 //! True if this texture has non-power-of-two dimensions.
239 bool IsRectangleTexture() const { return _bRectangle; }
240 //! True if this texture has non-power-of-two dimensions.
241 //! True if this pbuffer has a depth buffer.
242 bool HasDepth() const { return (_iNumDepthBits > 0); }
243 //! True if this pbuffer has a stencil buffer.
244 bool HasStencil() const { return (_iNumStencilBits > 0); }
245 //! True if this texture has mipmaps.
246 bool IsMipmapped() const { return _bMipmap; }
249 * @fn IsPowerOfTwo(int n)
250 * @brief Returns true if /param n is an integer power of 2.
252 * Taken from Steve Baker's Cute Code Collection.
253 * http://www.sjbaker.org/steve/software/cute_code.html
255 static bool IsPowerOfTwo(int n) { return ((n&(n-1))==0); }
258 /////////////////////////////////////////////////////////////////////////
259 // This is the deprecated (old) interface. It will likely be removed
260 // in a future version, so it is recommended that you transition to the
261 // new mode-string-based interface.
262 RenderTexture(int width, int height,
263 bool bIsTexture = true,
264 bool bIsDepthTexture = false);
266 // Call this once before use. Set bShare to true to share lists,
267 // textures, and program objects between the render texture context
268 // and the current active GL context. [deprecated]
269 bool Initialize(bool bShare = true,
271 bool bStencil = false,
272 bool bMipmap = false,
273 bool bAnisoFilter = false,
274 unsigned int iRBits = 8,
275 unsigned int iGBits = 8,
276 unsigned int iBBits = 8,
277 unsigned int iABits = 8,
278 // Only Win32 has RT now, so only make it default there
280 UpdateMode updateMode = RT_RENDER_TO_TEXTURE
282 UpdateMode updateMode = RT_COPY_TO_TEXTURE
285 // !Change the render texture resolution. [deprecated]
286 bool Reset(int iWidth, int iHeight);
288 /////////////////////////////////////////////////////////////////////////
291 protected: // methods
294 typedef std::pair<std::string, std::string> KeyVal;
296 void _ParseModeString(const char *modeString,
297 std::vector<int> &pixelFormatAttribs,
298 std::vector<int> &pbufferAttribs);
300 std::vector<int> _ParseBitVector(std::string bitVector);
301 KeyVal _GetKeyValuePair(std::string token);
304 bool _VerifyExtensions();
305 bool _InitializeTextures();
307 void _MaybeCopyBuffer();
308 bool _ReleaseBoundBuffers();
310 bool _BindDepthBuffer( ) const;
313 int _iWidth; // width of the pbuffer
314 int _iHeight; // height of the pbuffer
317 bool _bIsDepthTexture;
318 bool _bHasARBDepthTexture; // [Redge]
320 UpdateMode _eUpdateMode;
324 unsigned int _iNumAuxBuffers;
325 bool _bIsBufferBound;
326 int _iCurrentBoundBuffer;
328 unsigned int _iNumComponents;
329 unsigned int _iNumColorBits[4];
330 unsigned int _iNumDepthBits;
331 unsigned int _iNumStencilBits;
335 bool _bDoubleBuffered;
344 HDC _hDC; // Handle to a device context.
345 HGLRC _hGLContext; // Handle to a GL context.
346 HPBUFFERARB _hPBuffer; // Handle to a pbuffer.
349 HGLRC _hPreviousContext;
350 #elif defined( __MACH__ )
351 CGLContextObj _hGLContext;
352 CGLPBufferObj _hPBuffer;
354 CGLContextObj _hPreviousContext;
357 GLXContext _hGLContext;
358 GLXPbuffer _hPBuffer;
360 GLXDrawable _hPreviousDrawable;
361 GLXContext _hPreviousContext;
365 GLenum _iTextureTarget;
367 GLuint _iDepthTextureID;
369 unsigned short* _pPoorDepthTexture; // [Redge]
371 std::vector<int> _pixelFormatAttribs;
372 std::vector<int> _pbufferAttribs;
375 // Using these could lead to some odd behavior
376 RenderTexture(const RenderTexture&);
377 RenderTexture& operator=(const RenderTexture&);
380 #endif //__RENDERTEXTURE2_HPP__