]>
Dogcows Code - chaz/yoink/blob - src/texture.cc
2 /*******************************************************************************
4 Copyright (c) 2009, Charles McGarvey
7 Redistribution and use in source and binary forms, with or without
8 modification, are permitted provided that the following conditions are met:
10 * Redistributions of source code must retain the above copyright notice,
11 this list of conditions and the following disclaimer.
12 * Redistributions in binary form must reproduce the above copyright notice,
13 this list of conditions and the following disclaimer in the documentation
14 and/or other materials provided with the distribution.
16 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
20 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *******************************************************************************/
31 #include <boost/bind.hpp>
34 #include <SDL/SDL_image.h>
36 #include "mippleton.hh"
38 #include "dispatcher.hh"
48 * The texture implementation just contains all the information about the image
49 * which is worth having in memory. The image data itself is not worth keeping
50 * in memory if the texture has been loaded to GL, but the name of the resource
51 * is retained so that it can be reloaded if necessary. The implementation is a
52 * mippleton so that multiple texture objects can share the same internal
53 * objects and avoid having duplicate textures loaded to GL.
56 class texture::texture_impl
: public mippleton
<texture_impl
>
60 * Delete the texture (if it is loaded) from GL.
67 glDeleteTextures(1, &object_
);
73 * If the GL context was recreated, we probably need to reload the texture.
74 * This may involve reading it from disk again, but hopefully the OS was
75 * smart enough to cache it if the client has plenty of RAM.
78 void contextRecreated(const notification
& note
)
85 * This is a helper method used by some of the texture loading code. It
86 * returns the first power of two which is greater than the input value.
89 static int powerOfTwo(int input
)
103 * Construction is initialization.
106 explicit texture_impl(const std::string
& name
) :
107 mippleton
<texture_impl
>(name
),
111 minFilter_(GL_NEAREST
),
112 maxFilter_(GL_NEAREST
),
119 // we want to know when the GL context is recreated
120 dispatcher::instance().addHandler("video.context_recreated",
121 boost::bind(&texture_impl::contextRecreated
, this, _1
), this);
128 dispatcher::instance().removeHandler(this);
133 * Adapted from some public domain code. This stuff is common enough that
134 * it really should be included in SDL_image... We need this because images
135 * loaded with SDL_image aren't exactly GL-ready right out of the box. This
136 * method makes them ready.
139 static SDL_Surface
* prepareImageForGL(SDL_Surface
* surface
)
141 int w
= powerOfTwo(surface
->w
);
142 int h
= powerOfTwo(surface
->h
);
144 // 1. OpenGL images must (generally) have dimensions of a power-of-two.
145 // If this one doesn't, we can at least be more friendly by expanding
146 // the dimensions so that they are, though there will be some empty
147 // space within the range of normal texture coordinates. It's better of
148 // textures are the right size to begin with.
150 SDL_Surface
* image
= SDL_CreateRGBSurface
155 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
173 Uint32 savedFlags
= surface
->flags
&(SDL_SRCALPHA
|SDL_RLEACCELOK
);
174 Uint8 savedAlpha
= surface
->format
->alpha
;
175 if (savedFlags
& SDL_SRCALPHA
)
177 SDL_SetAlpha(surface
, 0, 0);
180 SDL_Rect srcArea
, destArea
;
181 srcArea
.x
= 0; destArea
.x
= 0;
182 srcArea
.y
= 0; destArea
.y
= h
- surface
->h
;
183 srcArea
.w
= surface
->w
;
184 srcArea
.h
= surface
->h
;
185 SDL_BlitSurface(surface
, &srcArea
, image
, &destArea
);
187 if (savedFlags
& SDL_SRCALPHA
)
189 SDL_SetAlpha(surface
, savedFlags
, savedAlpha
);
192 // 2. OpenGL textures make more sense within the coordinate system when
193 // they are "upside down," so let's flip it.
195 Uint8 line
[image
->pitch
];
197 Uint8
*pixels
= static_cast<Uint8
*>(image
->pixels
);
198 Uint16 pitch
= image
->pitch
;
200 int yend
= image
->h
- 1;
202 if (SDL_MUSTLOCK(image
)) SDL_LockSurface(image
);
203 while (ybegin
< yend
)
205 memcpy(line
, pixels
+ pitch
* ybegin
, pitch
);
206 memcpy(pixels
+ pitch
* ybegin
, pixels
+ pitch
* yend
, pitch
);
207 memcpy(pixels
+ pitch
* yend
, line
, pitch
);
211 if (SDL_MUSTLOCK(image
)) SDL_UnlockSurface(image
);
217 * Use SDL_image to load images from file. A surface with the image data is
219 * @return Image data.
222 SDL_Surface
* loadImageData()
224 SDL_Surface
* surface
;
226 surface
= IMG_Load(texture::getPathToResource(getName()).c_str());
230 throw texture::exception("loading failed");
233 SDL_Surface
* temp
= prepareImageForGL(surface
);
234 SDL_FreeSurface(surface
);
238 throw texture::exception("image couldn't be prepared for GL");
241 if (temp
->format
->BytesPerPixel
== 3)
245 else if (temp
->format
->BytesPerPixel
== 4)
251 SDL_FreeSurface(temp
);
252 throw texture::exception("image is not the required 24 or 32 bpp");
263 * Upload the image to GL so that it will be accessible by a much more
264 * manageable handle and hopefully reside in video memory.
275 SDL_Surface
* imageData
= loadImageData();
277 glGenTextures(1, &object_
);
278 glBindTexture(GL_TEXTURE_2D
, object_
);
295 SDL_FreeSurface(imageData
);
300 * Sets some texture properties such as the filters and external coordinate
306 glTexParameteri(GL_TEXTURE_2D
, GL_TEXTURE_MIN_FILTER
, minFilter_
);
307 glTexParameteri(GL_TEXTURE_2D
, GL_TEXTURE_MAG_FILTER
, maxFilter_
);
308 glTexParameteri(GL_TEXTURE_2D
, GL_TEXTURE_WRAP_S
, wrapU_
);
309 glTexParameteri(GL_TEXTURE_2D
, GL_TEXTURE_WRAP_T
, wrapV_
);
313 unsigned width_
; ///< Horizontal dimension of the image.
314 unsigned height_
; ///< Vertical dimension.
316 GLuint mode_
; ///< Depth of the image, GL_RGB or GL_RGBA.
317 GLuint minFilter_
; ///< Filter.
318 GLuint maxFilter_
; ///< Filter.
319 GLuint wrapU_
; ///< Wrapping behavior horizontally.
320 GLuint wrapV_
; ///< Wrapping behavior vertically.
321 GLuint object_
; ///< GL texture handle.
325 texture::texture(const std::string
& name
) :
327 impl(texture::texture_impl::retain(name
), &texture::texture_impl::release
)
332 * Bind the GL texture for mapping, etc.
337 glBindTexture(GL_TEXTURE_2D
, getObject());
342 * Get the texture object, for the curious.
345 GLuint
texture::getObject()
348 return impl
->object_
;
352 unsigned texture::getWidth()
358 unsigned texture::getHeight()
361 return impl
->height_
;
365 void texture::setMinFilter(GLuint filter
)
367 impl
->minFilter_
= filter
;
370 void texture::setMaxFilter(GLuint filter
)
372 impl
->maxFilter_
= filter
;
375 void texture::setWrapU(GLuint wrap
)
380 void texture::setWrapV(GLuint wrap
)
386 void texture::applyChanges()
389 impl
->setProperties();
393 std::string
texture::getPathToResource(const std::string
& name
)
395 // TODO since this is a generic library class, more than PNG should be
397 return resource::getPathToResource("textures/" + name
+ ".png");
403 /** vim: set ts=4 sw=4 tw=80: *************************************************/
This page took 0.054841 seconds and 4 git commands to generate.