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
49 #include <simgear/compiler.h>
60 /* The pixel format for the pbuffer is controlled by the mode string passed
61 * into the PBuffer constructor. This string can have the following attributes:
63 * To specify the pixel format, use the following syntax.
65 * <channels> must match one of the following.
67 * r - r pixel format (for float buffer).
68 * rg - rg pixel format (for float buffer).
69 * rgb - rgb pixel format. 8 bit or 16/32 bit in float buffer mode
70 * rgba - same as "rgb alpha" string
72 * <bits> can either be a scalar--meaning the same bit depth for each
73 * channel-- or a 2-, 3-, 4-component vector matching the specified number of
74 * channels. Vector components should be comma separated. An optional 'f'
75 * suffix on the bit depth specifies float components. In this case <bits>
76 * must be either "32f" or "16f". If <bits> is empty, the default 8 bits per
77 * channel will be used.
83 * The following other attributes are supported.
85 * depth=n - must have n-bit depth buffer, omit n for default (24 bits)
86 * stencil=n - must have n-bit stencil buffer, omit n for default (8 bits)
87 * samples=n - must support n-sample antialiasing (n can be 2 or 4)
88 * aux=n - must have n AUX buffers
89 * doublebuffer - must support double buffered rendering
93 * texCUBE - must support binding pbuffer as texture to specified target
94 * - binding the depth buffer is also supported by specifying
98 * - Both depth and color texture binding, may be specified, but
99 * the targets must match!
100 * For example: "tex2D depthTex2D" or "texRECT depthTexRECT"
103 * ctt - These mutually exclusive options specify the update method used
104 * for render textures that support texture binding. "rtt"
105 * indicates that render to texture will be used to update the
106 * texture. "ctt" indicates that copy to texture will be used
107 * (i.e. glCopyTexSubImage2D()). "rtt" is the default if neither is
108 * specified, and one of the "tex*" options above is.
111 *---------------------------------------------------------------------------
115 * * Texture Parameters:
116 * The default texture wrap mode is GL_CLAMP_TO_EDGE for all textures, and
117 * the default texture filtering modes (min and mag) are GL_NEAREST.
118 * To change these parameters, simply bind the RenderTexture (using the
119 * Bind() method), and set them the way you would for any GL texture object.
120 * The same goes for depth textures.
122 * * Enabling Mipmapping:
123 * This is similar to the texture parameters above. When "rtt" is specified
124 * in the mode string, "mipmap" must also be specified in order to enable
125 * a mipmapped pbuffer. Then, the mipmaps must be created by enabling the
126 * GL_SGIS_GENERATE_MIPMAP texture parameter in the same way as above, and
127 * the min filter mode must be set to a mipmap filter mode, as with any
128 * mipmapped texture object.
130 * * Enabling Anisotropic Filtering
131 * As with the texture parameters above, except as in the following code:
132 * glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, max);
133 * glTexParameterf(target, GL_TEXTURE_MAX_ANISOTROPY_EXT, <value < max>);
140 RT_RENDER_TO_TEXTURE,
146 RenderTexture(const char *strMode="rgb tex2D");
149 //! Call this once before use. Set bShare to true to share lists, textures,
150 //! and program objects between the render texture context and the
151 //! current active GL context.
152 bool Initialize(int width, int height,
153 bool shareObjects=true,
154 bool copyContext=false);
156 // !Change the render texture format.
157 bool Reset(const char* strMode,...);
158 // !Change the size of the render texture.
159 bool Resize(int width, int height);
161 // !Begin drawing to the texture. (i.e. use as "output" texture)
163 // !Ends drawing to 'current', begins drawing to this RenderTexture
164 bool BeginCapture(RenderTexture* current);
165 // !End drawing to the texture.
168 // !Bind the texture to the active texture unit for use as an "input" texture
171 // !Bind the depth texture to the active texture unit for use as an "input" texture
172 void BindDepth() const;
174 // !Associate the RTT texture with 'iBuffer' (default is WGL_FRONT_LEFT_ARB)
175 bool BindBuffer( int iBuffer );
177 //! Enables the texture target appropriate for this render texture.
178 void EnableTextureTarget() const
179 { if (_bInitialized) glEnable(_iTextureTarget); }
180 //! Disables the texture target appropriate for this render texture.
181 void DisableTextureTarget() const
182 { if (_bInitialized) glDisable(_iTextureTarget); }
184 //! Returns the texture ID. Useful in Cg applications.
185 unsigned int GetTextureID() const { return _iTextureID; }
186 //! Returns the depth texture ID. Useful in Cg applications.
187 unsigned int GetDepthTextureID() const { return _iDepthTextureID; }
188 //! Returns the texture target this texture is bound to.
189 unsigned int GetTextureTarget() const { return _iTextureTarget; }
190 //! Conversion operator allows RenderTexture to be passed to GL calls
191 operator unsigned int()const{return _iTextureID;}
193 //! Returns the width of the offscreen buffer.
194 int GetWidth() const { return _iWidth; }
195 //! Returns the width of the offscreen buffer.
196 int GetHeight() const { return _iHeight; }
197 //! Returns the maximum S texture coordinate.
198 int GetMaxS() const { return IsRectangleTexture() ? _iWidth : 1; }
199 //! Returns the maximum T texture coordinate.
200 int GetMaxT() const { return IsRectangleTexture() ? _iHeight : 1; }
202 //! Returns the number of red bits allocated.
203 int GetRedBits() const { return _iNumColorBits[0]; }
204 //! Returns the number of green bits allocated.
205 int GetGreenBits() const { return _iNumColorBits[1]; }
206 //! Returns the number of blue bits allocated.
207 int GetBlueBits() const { return _iNumColorBits[2]; }
208 //! Returns the number of alpha bits allocated.
209 int GetAlphaBits() const { return _iNumColorBits[3]; }
211 //! Returns the number of depth bits allocated.
212 int GetDepthBits() const { return _iNumDepthBits; }
213 //! Returns the number of stencil bits allocated.
214 int GetStencilBits() const { return _iNumStencilBits; }
216 //! True if this RenderTexture has been properly initialized.
217 bool IsInitialized() const { return _bInitialized; }
218 //! True if this is a texture and not just an offscreen buffer.
219 bool IsTexture() const { return _bIsTexture; }
220 //! True if this is a depth texture and not just an offscreen buffer.
221 bool IsDepthTexture() const { return _bIsDepthTexture; }
222 //! True if this is a floating point buffer / texture.
223 bool IsFloatTexture() const { return _bFloat; }
224 //! True if this is a double-buffered pbuffer
225 bool IsDoubleBuffered() const { return _bDoubleBuffered; }
226 //! True if this texture has non-power-of-two dimensions.
227 bool IsRectangleTexture() const { return _bRectangle; }
228 //! True if this texture has non-power-of-two dimensions.
229 //! True if this pbuffer has a depth buffer.
230 bool HasDepth() const { return (_iNumDepthBits > 0); }
231 //! True if this pbuffer has a stencil buffer.
232 bool HasStencil() const { return (_iNumStencilBits > 0); }
233 //! True if this texture has mipmaps.
234 bool IsMipmapped() const { return _bMipmap; }
237 * @fn IsPowerOfTwo(int n)
238 * @brief Returns true if /param n is an integer power of 2.
240 * Taken from Steve Baker's Cute Code Collection.
241 * http://www.sjbaker.org/steve/software/cute_code.html
243 static bool IsPowerOfTwo(int n) { return ((n&(n-1))==0); }
246 /////////////////////////////////////////////////////////////////////////
247 // This is the deprecated (old) interface. It will likely be removed
248 // in a future version, so it is recommended that you transition to the
249 // new mode-string-based interface.
250 RenderTexture(int width, int height,
251 bool bIsTexture = true,
252 bool bIsDepthTexture = false);
254 // Call this once before use. Set bShare to true to share lists,
255 // textures, and program objects between the render texture context
256 // and the current active GL context. [deprecated]
257 bool Initialize(bool bShare = true,
259 bool bStencil = false,
260 bool bMipmap = false,
261 bool bAnisoFilter = false,
262 unsigned int iRBits = 8,
263 unsigned int iGBits = 8,
264 unsigned int iBBits = 8,
265 unsigned int iABits = 8,
266 // Only Win32 has RT now, so only make it default there
268 UpdateMode updateMode = RT_RENDER_TO_TEXTURE
270 UpdateMode updateMode = RT_COPY_TO_TEXTURE
273 // !Change the render texture resolution. [deprecated]
274 bool Reset(int iWidth, int iHeight);
276 /////////////////////////////////////////////////////////////////////////
279 protected: // methods
282 typedef std::pair<std::string, std::string> KeyVal;
284 void _ParseModeString(const char *modeString,
285 std::vector<int> &pixelFormatAttribs,
286 std::vector<int> &pbufferAttribs);
288 std::vector<int> _ParseBitVector(std::string bitVector);
289 KeyVal _GetKeyValuePair(std::string token);
292 bool _VerifyExtensions();
293 bool _InitializeTextures();
295 void _MaybeCopyBuffer();
296 bool _ReleaseBoundBuffers();
298 bool _BindDepthBuffer( ) const;
301 int _iWidth; // width of the pbuffer
302 int _iHeight; // height of the pbuffer
305 bool _bIsDepthTexture;
306 bool _bHasARBDepthTexture; // [Redge]
308 UpdateMode _eUpdateMode;
312 unsigned int _iNumAuxBuffers;
313 bool _bIsBufferBound;
314 int _iCurrentBoundBuffer;
316 unsigned int _iNumComponents;
317 unsigned int _iNumColorBits[4];
318 unsigned int _iNumDepthBits;
319 unsigned int _iNumStencilBits;
323 bool _bDoubleBuffered;
332 HDC _hDC; // Handle to a device context.
333 HGLRC _hGLContext; // Handle to a GL context.
334 HPBUFFERARB _hPBuffer; // Handle to a pbuffer.
337 HGLRC _hPreviousContext;
340 GLXContext _hGLContext;
341 GLXPbuffer _hPBuffer;
343 GLXDrawable _hPreviousDrawable;
344 GLXContext _hPreviousContext;
348 GLenum _iTextureTarget;
349 unsigned int _iTextureID;
350 unsigned int _iDepthTextureID;
352 unsigned short* _pPoorDepthTexture; // [Redge]
354 std::vector<int> _pixelFormatAttribs;
355 std::vector<int> _pbufferAttribs;
358 // Using these could lead to some odd behavior
359 RenderTexture(const RenderTexture&);
360 RenderTexture& operator=(const RenderTexture&);
363 #endif //__RENDERTEXTURE2_HPP__