Advanced-Data.html (21380B)
1 <!DOCTYPE html> 2 <html lang="ja"> 3 <head> 4 <meta charset="utf-8"/> 5 <title>LearnOpenGL</title> 6 <link rel="shortcut icon" type="image/ico" href="/favicon.ico" /> 7 <link rel="stylesheet" href="../static/style.css" /> 8 <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js"> </script> 9 <script src="/static/functions.js"></script> 10 </head> 11 <body> 12 <nav> 13 <ol> 14 <li id="Introduction"> 15 <a href="https://learnopengl.com/Introduction">はじめに</a> 16 </li> 17 <li id="Getting-started"> 18 <span class="closed">入門</span> 19 <ol> 20 <li id="Getting-started/OpenGL"> 21 <a href="https://learnopengl.com/Getting-started/OpenGL">OpenGL </a> 22 </li> 23 <li id="Getting-started/Creating-a-window"> 24 <a href="https://learnopengl.com/Getting-started/Creating-a-window">ウィンドウの作成</a> 25 </li> 26 <li id="Getting-started/Hello-Window"> 27 <a href="https://learnopengl.com/Getting-started/Hello-Window">最初のウィンドウ</a> 28 </li> 29 <li id="Getting-started/Hello-Triangle"> 30 <a href="https://learnopengl.com/Getting-started/Hello-Triangle">最初の三角形</a> 31 </li> 32 <li id="Getting-started/Shaders"> 33 <a href="https://learnopengl.com/Getting-started/Shaders">シェーダー</a> 34 </li> 35 <li id="Getting-started/Textures"> 36 <a href="https://learnopengl.com/Getting-started/Textures">テクスチャ</a> 37 </li> 38 <li id="Getting-started/Transformations"> 39 <a href="https://learnopengl.com/Getting-started/Transformations">座標変換</a> 40 </li> 41 <li id="Getting-started/Coordinate-Systems"> 42 <a href="https://learnopengl.com/Getting-started/Coordinate-Systems">座標系</a> 43 </li> 44 <li id="Getting-started/Camera"> 45 <a href="https://learnopengl.com/Getting-started/Camera">カメラ</a> 46 </li> 47 <li id="Getting-started/Review"> 48 <a href="https://learnopengl.com/Getting-started/Review">まとめ</a> 49 </li> 50 </ol> 51 </li> 52 <li id="Lighting"> 53 <span class="closed">Lighting </span> 54 <ol> 55 <li id="Lighting/Colors"> 56 <a href="https://learnopengl.com/Lighting/Colors">Colors </a> 57 </li> 58 <li id="Lighting/Basic-Lighting"> 59 <a href="https://learnopengl.com/Lighting/Basic-Lighting">Basic Lighting </a> 60 </li> 61 <li id="Lighting/Materials"> 62 <a href="https://learnopengl.com/Lighting/Materials">Materials </a> 63 </li> 64 <li id="Lighting/Lighting-maps"> 65 <a href="https://learnopengl.com/Lighting/Lighting-maps">Lighting maps </a> 66 </li> 67 <li id="Lighting/Light-casters"> 68 <a href="https://learnopengl.com/Lighting/Light-casters">Light casters </a> 69 </li> 70 <li id="Lighting/Multiple-lights"> 71 <a href="https://learnopengl.com/Lighting/Multiple-lights">Multiple lights </a> 72 </li> 73 <li id="Lighting/Review"> 74 <a href="https://learnopengl.com/Lighting/Review">Review </a> 75 </li> 76 </ol> 77 </li> 78 <li id="Model-Loading"> 79 <span class="closed">Model Loading </span> 80 <ol> 81 <li id="Model-Loading/Assimp"> 82 <a href="https://learnopengl.com/Model-Loading/Assimp">Assimp </a> 83 </li> 84 <li id="Model-Loading/Mesh"> 85 <a href="https://learnopengl.com/Model-Loading/Mesh">Mesh </a> 86 </li> 87 <li id="Model-Loading/Model"> 88 <a href="https://learnopengl.com/Model-Loading/Model">Model </a> 89 </li> 90 </ol> 91 </li> 92 <li id="Advanced-OpenGL"> 93 <span class="closed">Advanced OpenGL </span> 94 <ol> 95 <li id="Advanced-OpenGL/Depth-testing"> 96 <a href="https://learnopengl.com/Advanced-OpenGL/Depth-testing">Depth testing </a> 97 </li> 98 <li id="Advanced-OpenGL/Stencil-testing"> 99 <a href="https://learnopengl.com/Advanced-OpenGL/Stencil-testing">Stencil testing </a> 100 </li> 101 <li id="Advanced-OpenGL/Blending"> 102 <a href="https://learnopengl.com/Advanced-OpenGL/Blending">Blending </a> 103 </li> 104 <li id="Advanced-OpenGL/Face-culling"> 105 <a href="https://learnopengl.cm/Advanced-OpenGL/Face-culling">Face culling </a> 106 </li> 107 <li id="Advanced-OpenGL/Framebuffers"> 108 <a href="https://learnopengl.com/Advanced-OpenGL/Framebuffers">Framebuffers </a> 109 </li> 110 <li id="Advanced-OpenGL/Cubemaps"> 111 <a href="https://learnopengl.com/Advanced-OpenGL/Cubemaps">Cubemaps </a> 112 </li> 113 <li id="Advanced-OpenGL/Advanced-Data"> 114 <a href="https://learnopengl.com/Advanced-OpenGL/Advanced-Data">Advanced Data </a> 115 </li> 116 <li id="Advanced-OpenGL/Advanced-GLSL"> 117 <a href="https://learnopengl.com/Advanced-OpenGL/Advanced-GLSL">Advanced GLSL </a> 118 </li> 119 <li id="Advanced-OpenGL/Geometry-Shader"> 120 <a href="https://learnopengl.com/Advanced-OpenGL/Geometry-Shader">Geometry Shader </a> 121 </li> 122 <li id="Advanced-OpenGL/Instancing"> 123 <a href="https://learnopengl.com/Advanced-OpenGL/Instancing">Instancing </a> 124 </li> 125 <li id="Advanced-OpenGL/Anti-Aliasing"> 126 <a href="https://learnopengl.com/Advanced-OpenGL/Anti-Aliasing">Anti Aliasing </a> 127 </li> 128 </ol> 129 </li> 130 <li id="Advanced-Lighting"> 131 <span class="closed">Advanced Lighting </span> 132 <ol> 133 <li id="Advanced-Lighting/Advanced-Lighting"> 134 <a href="https://learnopengl.com/Advanced-Lighting/Advanced-Lighting">Advanced Lighting </a> 135 </li> 136 <li id="Advanced-Lighting/Gamma-Correction"> 137 <a href="https://learnopengl.com/Advanced-Lighting/Gamma-Correction">Gamma Correction </a> 138 </li> 139 <li id="Advanced-Lighting/Shadows"> 140 <span class="closed">Shadows </span> 141 <ol> 142 <li id="Advanced-Lighting/Shadows/Shadow-Mapping"> 143 <a href="https://learnopengl.com/Advanced-Lighting/Shadows/Shadow-Mapping">Shadow Mapping </a> 144 </li> 145 <li id="Advanced-Lighting/Shadows/Point-Shadows"> 146 <a href="https://learnopengl.com/Advanced-Lighting/Shadows/Point-Shadows">Point Shadows </a> 147 </li> 148 </ol> 149 </li> 150 <li id="Advanced-Lighting/Normal-Mapping"> 151 <a href="https://learnopengl.com/Advanced-Lighting/Normal-Mapping">Normal Mapping </a> 152 </li> 153 <li id="Advanced-Lighting/Parallax-Mapping"> 154 <a href="https://learnopengl.com/Advanced-Lighting/Parallax-Mapping">Parallax Mapping </a> 155 </li> 156 <li id="Advanced-Lighting/HDR"> 157 <a href="https://learnopengl.com/Advanced-Lighting/HDR">HDR </a> 158 </li> 159 <li id="Advanced-Lighting/Bloom"> 160 <a href="https://learnopengl.com/Advanced-Lighting/Bloom">Bloom </a> 161 </li> 162 <li id="Advanced-Lighting/Deferred-Shading"> 163 <a href="https://learnopengl.com/Advanced-Lighting/Deferred-Shading">Deferred Shading </a> 164 </li> 165 <li id="Advanced-Lighting/SSAO"> 166 <a href="https://learnopengl.com/Advanced-Lighting/SSAO">SSAO </a> 167 </li> 168 </ol> 169 </li> 170 <li id="PBR"> 171 <span class="closed">PBR </span> 172 <ol> 173 <li id="PBR/Theory"> 174 <a href="https://learnopengl.com/PBR/Theory">Theory </a> 175 </li> 176 <li id="PBR/Lighting"> 177 <a href="https://learnopengl.com/PBR/Lighting">Lighting </a> 178 </li> 179 <li id="PBR/IBL"> 180 <span class="closed">IBL </span> 181 <ol> 182 <li id="PBR/IBL/Diffuse-irradiance"> 183 <a href="https://learnopengl.com/PBR/IBL/Diffuse-irradiance">Diffuse irradiance </a> 184 </li> 185 <li id="PBR/IBL/Specular-IBL"> 186 <a href="https://learnopengl.com/PBR/IBL/Specular-IBL">Specular IBL </a> 187 </li> 188 </ol> 189 </li> 190 </ol> 191 </li> 192 <li id="In-Practice"> 193 <span class="closed">In Practice </span> 194 <ol> 195 <li id="In-Practice/Debugging"> 196 <a href="https://learnopengl.com/In-Practice/Debugging">Debugging </a> 197 </li> 198 <li id="In-Practice/Text-Rendering"> 199 <a href="https://learnopengl.com/In-Practice/Text-Rendering">Text Rendering </a> 200 </li> 201 <li id="In-Practice/2D-Game"> 202 <span class="closed">2D Game </span> 203 <ol> 204 <li id="In-Practice/2D-Game/Breakout"> 205 <a href="https://learnopengl.com/In-Practice/2D-Game/Breakout">Breakout </a> 206 </li> 207 <li id="In-Practice/2D-Game/Setting-up"> 208 <a href="https://learnopengl.com/In-Practice/2D-Game/Setting-up">Setting up </a> 209 </li> 210 <li id="In-Practice/2D-Game/Rendering-Sprites"> 211 <a href="https://learnopengl.com/In-Practice/2D-Game/Rendering-Sprites">Rendering Sprites </a> 212 </li> 213 <li id="In-Practice/2D-Game/Levels"> 214 <a href="https://learnopengl.com/In-Practice/2D-Game/Levels">Levels </a> 215 </li> 216 <li id="In-Practice/2D-Game/Collisions"> 217 <span class="closed">Collisions </span> 218 <ol> 219 <li id="In-Practice/2D-Game/Collisions/Ball"> 220 <a href="https://learnopengl.com/In-Practice/2D-Game/Collisions/Ball">Ball </a> 221 </li> 222 <li id="In-Practice/2D-Game/Collisions/Collision-detection"> 223 <a href="https://learnopengl.com/In-Practice/2D-Game/Collisions/Collision-detection">Collision detection </a> 224 </li> 225 <li id="In-Practice/2D-Game/Collisions/Collision-resolution"> 226 <a href="https://learnopengl.com/In-Practice/2D-Game/Collisions/Collision-resolution">Collision resolution </a> 227 </li> 228 </ol> 229 </li> 230 <li id="In-Practice/2D-Game/Particles"> 231 <a href="https://learnopengl.com/In-Practice/2D-Game/Particles">Particles </a> 232 </li> 233 <li id="In-Practice/2D-Game/Postprocessing"> 234 <a href="https://learnopengl.com/In-Practice/2D-Game/Postprocessing">Postprocessing </a> 235 </li> 236 <li id="In-Practice/2D-Game/Powerups"> 237 <a href="https://learnopengl.com/In-Practice/2D-Game/Powerups">Powerups </a> 238 </li> 239 <li id="In-Practice/2D-Game/Audio"> 240 <a href="https://learnopengl.com/In-Practice/2D-Game/Audio">Audio </a> 241 </li> 242 <li id="In-Practice/2D-Game/Render-text"> 243 <a href="https://learnopengl.com/In-Practice/2D-Game/Render-text">Render text </a> 244 </li> 245 <li id="In-Practice/2D-Game/Final-thoughts"> 246 <a href="https://learnopengl.com/In-Practice/2D-Game/Final-thoughts">Final thoughts </a> 247 </li> 248 </ol> 249 </li> 250 </ol> 251 </li> 252 <li id="Guest-Articles"> 253 <span class="closed">Guest Articles </span> 254 <ol> 255 <li id="Guest-Articles/How-to-publish"> 256 <a href="https://learnopengl.com/Guest-Articles/How-to-publish">How to publish </a> 257 </li> 258 <li id="Guest-Articles/2020"> 259 <span class="closed">2020 </span> 260 <ol> 261 <li id="Guest-Articles/2020/OIT"> 262 <span class="closed">OIT </span> 263 <ol> 264 <li id="Guest-Articles/2020/OIT/Introduction"> 265 <a href="https://learnopengl.com/Guest-Articles/2020/OIT/Introduction">Introduction </a> 266 </li> 267 <li id="Guest-Articles/2020/OIT/Weighted-Blended"> 268 <a href="https://learnopengl.com/Guest-Articles/2020/OIT/Weighted-Blended">Weighted Blended </a> 269 </li> 270 </ol> 271 </li> 272 <li id="Guest-Articles/2020/Skeletal-Animation"> 273 <a href="https://learnopengl.com/Guest-Articles/2020/Skeletal-Animation">Skeletal Animation </a> 274 </li> 275 </ol> 276 </li> 277 <li id="Guest-Articles/2021"> 278 <span class="closed">2021 </span> 279 <ol> 280 <li id="Guest-Articles/2021/CSM"> 281 <a href="https://learnopengl.com/Guest-Articles/2021/CSM">CSM </a> 282 </li> 283 <li id="Guest-Articles/2021/Scene"> 284 <span class="closed">Scene </span> 285 <ol> 286 <li id="Guest-Articles/2021/Scene/Scene-Graph"> 287 <a href="https://learnopengl.com/Guest-Articles/2021/Scene/Scene-Graph">Scene Graph </a> 288 </li> 289 <li id="Guest-Articles/2021/Scene/Frustum-Culling"> 290 <a href="https://learnopengl.com/Guest-Articles/2021/Scene/Frustum-Culling">Frustum Culling </a> 291 </li> 292 </ol> 293 </li> 294 <li id="Guest-Articles/2021/Tessellation"> 295 <span class="closed">Tessellation </span> 296 <ol> 297 <li id="Guest-Articles/2021/Tessellation/Height-map"> 298 <a href="https://learnopengl.com/Guest-Articles/2021/Tessellation/Height-map">Height map </a> 299 </li> 300 </ol> 301 </li> 302 </ol> 303 </li> 304 </ol> 305 </li> 306 <li id="Code-repository"> 307 <a href="https://learnopengl.com/Code-repository">Code repository </a> 308 </li> 309 <li id="Translations"> 310 <a href="https://learnopengl.com/Translations">Translations </a> 311 </li> 312 <li id="About"> 313 <a href="https://learnopengl.com/About">About </a> 314 </li> 315 </ol> 316 </nav> 317 <main> 318 <div id="content"> 319 <h1 id="content-title">Advanced Data</h1> 320 <h1 id="content-url" style='display:none;'>Advanced-OpenGL/Advanced-Data</h1> 321 <p> 322 Throughout most chapters we've been extensively using buffers in OpenGL to store data on the GPU. This chapter we'll briefly discuss a few alternative approaches to managing buffers. 323 </p> 324 325 <p> 326 A buffer in OpenGL is, at its core, an object that manages a certain piece of GPU memory and nothing more. We give meaning to a buffer when binding it to a specific <def>buffer target</def>. A buffer is only a vertex array buffer when we bind it to <var>GL_ARRAY_BUFFER</var>, but we could just as easily bind it to <var>GL_ELEMENT_ARRAY_BUFFER</var>. OpenGL internally stores a reference to the buffer per target and, based on the target, processes the buffer differently. 327 </p> 328 329 <p> 330 So far we've been filling the buffer's memory by calling <fun><function id='31'>glBufferData</function></fun>, which allocates a piece of GPU memory and adds data into this memory. If we were to pass <code>NULL</code> as its data argument, the function would only allocate memory and not fill it. This is useful if we first want to <em>reserve</em> a specific amount of memory and later come back to this buffer. 331 </p> 332 333 <p> 334 Instead of filling the entire buffer with one function call we can also fill specific regions of the buffer by calling <fun><function id='90'>glBufferSubData</function></fun>. This function expects a buffer target, an offset, the size of the data and the actual data as its arguments. What's new with this function is that we can now give an offset that specifies from <em>where</em> we want to fill the buffer. This allows us to insert/update only certain parts of the buffer's memory. Do note that the buffer should have enough allocated memory so a call to <fun><function id='31'>glBufferData</function></fun> is necessary before calling <fun><function id='90'>glBufferSubData</function></fun> on the buffer. 335 </p> 336 337 <pre><code> 338 <function id='90'>glBufferSubData</function>(GL_ARRAY_BUFFER, 24, sizeof(data), &data); // Range: [24, 24 + sizeof(data)] 339 </code></pre> 340 341 <p> 342 Yet another method for getting data into a buffer is to ask for a pointer to the buffer's memory and directly copy the data in memory yourself. By calling <fun><function id='91'>glMapBuffer</function></fun> OpenGL returns a pointer to the currently bound buffer's memory for us to operate on: 343 </p> 344 345 <pre><code> 346 float data[] = { 347 0.5f, 1.0f, -0.35f 348 [...] 349 }; 350 <function id='32'>glBindBuffer</function>(GL_ARRAY_BUFFER, buffer); 351 // get pointer 352 void *ptr = <function id='91'>glMapBuffer</function>(GL_ARRAY_BUFFER, GL_WRITE_ONLY); 353 // now copy data into memory 354 memcpy(ptr, data, sizeof(data)); 355 // make sure to tell OpenGL we're done with the pointer 356 <function id='92'>glUnmapBuffer</function>(GL_ARRAY_BUFFER); 357 </code></pre> 358 359 <p> 360 By telling OpenGL we're finished with the pointer operations via <fun><function id='92'>glUnmapBuffer</function></fun>, OpenGL knows you're done. By unmapping, the pointer becomes invalid and the function returns <var>GL_TRUE</var> if OpenGL was able to map your data successfully to the buffer. 361 </p> 362 363 <p> 364 Using <fun><function id='91'>glMapBuffer</function></fun> is useful for directly mapping data to a buffer, without first storing it in temporary memory. Think of directly reading data from file and copying it into the buffer's memory. 365 </p> 366 367 <h2>Batching vertex attributes</h2> 368 <p> 369 Using <fun><function id='30'>glVertexAttribPointer</function></fun> we were able to specify the attribute layout of the vertex array buffer's content. Within the vertex array buffer we <def>interleaved</def> the attributes; that is, we placed the position, normal and/or texture coordinates next to each other in memory for each vertex. Now that we know a bit more about buffers we can take a different approach. 370 </p> 371 372 <p> 373 What we could also do is batch all the vector data into large chunks per attribute type instead of interleaving them. Instead of an interleaved layout <code>123123123123</code> we take a batched approach <code>111122223333</code>. 374 </p> 375 376 <p> 377 When loading vertex data from file you generally retrieve an array of positions, an array of normals and/or an array of texture coordinates. It may cost some effort to combine these arrays into one large array of interleaved data. Taking the batching approach is then an easier solution that we can easily implement using <fun><function id='90'>glBufferSubData</function></fun>: 378 </p> 379 380 <pre><code> 381 float positions[] = { ... }; 382 float normals[] = { ... }; 383 float tex[] = { ... }; 384 // fill buffer 385 <function id='90'>glBufferSubData</function>(GL_ARRAY_BUFFER, 0, sizeof(positions), &positions); 386 <function id='90'>glBufferSubData</function>(GL_ARRAY_BUFFER, sizeof(positions), sizeof(normals), &normals); 387 <function id='90'>glBufferSubData</function>(GL_ARRAY_BUFFER, sizeof(positions) + sizeof(normals), sizeof(tex), &tex); 388 </code></pre> 389 390 <p> 391 This way we can directly transfer the attribute arrays as a whole into the buffer without first having to process them. We could have also combined them in one large array and fill the buffer right away using <fun><function id='31'>glBufferData</function></fun>, but using <fun><function id='90'>glBufferSubData</function></fun> lends itself perfectly for tasks like these. 392 </p> 393 <p> 394 We'll also have to update the vertex attribute pointers to reflect these changes: 395 </p> 396 397 <pre><code> 398 <function id='30'>glVertexAttribPointer</function>(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), 0); 399 <function id='30'>glVertexAttribPointer</function>(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)(sizeof(positions))); 400 <function id='30'>glVertexAttribPointer</function>( 401 2, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)(sizeof(positions) + sizeof(normals))); 402 </code></pre> 403 404 <p> 405 Note that the <code>stride</code> parameter is equal to the size of the vertex attribute, since the next vertex attribute vector can be found directly after its 3 (or 2) components. 406 </p> 407 408 <p> 409 This gives us yet another approach of setting and specifying vertex attributes. Using either approach is feasible, it is mostly a more organized way to set vertex attributes. However, the interleaved approach is still the recommended approach as the vertex attributes for each vertex shader run are then closely aligned in memory. 410 </p> 411 412 <h2>Copying buffers</h2> 413 <p> 414 Once your buffers are filled with data you may want to share that data with other buffers or perhaps copy the buffer's content into another buffer. The function <fun><function id='93'>glCopyBufferSubData</function></fun> allows us to copy the data from one buffer to another buffer with relative ease. The function's prototype is as follows: 415 </p> 416 417 <pre><code> 418 void <function id='93'>glCopyBufferSubData</function>(GLenum readtarget, GLenum writetarget, GLintptr readoffset, 419 GLintptr writeoffset, GLsizeiptr size); 420 </code></pre> 421 422 <p> 423 The <code>readtarget</code> and <code>writetarget</code> parameters expect to give the buffer targets that we want to copy from and to. We could for example copy from a <var>VERTEX_ARRAY_BUFFER</var> buffer to a <var>VERTEX_ELEMENT_ARRAY_BUFFER</var> buffer by specifying those buffer targets as the read and write targets respectively. The buffers currently bound to those buffer targets will then be affected. 424 </p> 425 426 <p> 427 But what if we wanted to read and write data into two different buffers that are both vertex array buffers? We can't bind two buffers at the same time to the same buffer target. For this reason, and this reason alone, OpenGL gives us two more buffer targets called <var>GL_COPY_READ_BUFFER</var> and <var>GL_COPY_WRITE_BUFFER</var>. We then bind the buffers of our choice to these new buffer targets and set those targets as the <code>readtarget</code> and <code>writetarget</code> argument. 428 </p> 429 430 <p> 431 <fun><function id='93'>glCopyBufferSubData</function></fun> then reads data of a given <code>size</code> from a given <code>readoffset</code> and writes it into the <code>writetarget</code> buffer at <code>writeoffset</code>. An example of copying the content of two vertex array buffers is shown below: 432 </p> 433 434 <pre><code> 435 <function id='32'>glBindBuffer</function>(GL_COPY_READ_BUFFER, vbo1); 436 <function id='32'>glBindBuffer</function>(GL_COPY_WRITE_BUFFER, vbo2); 437 <function id='93'>glCopyBufferSubData</function>(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, 0, 0, 8 * sizeof(float)); 438 </code></pre> 439 440 <p> 441 We could've also done this by only binding the <code>writetarget</code> buffer to one of the new buffer target types: 442 </p> 443 444 <pre><code> 445 float vertexData[] = { ... }; 446 <function id='32'>glBindBuffer</function>(GL_ARRAY_BUFFER, vbo1); 447 <function id='32'>glBindBuffer</function>(GL_COPY_WRITE_BUFFER, vbo2); 448 <function id='93'>glCopyBufferSubData</function>(GL_ARRAY_BUFFER, GL_COPY_WRITE_BUFFER, 0, 0, 8 * sizeof(float)); 449 </code></pre> 450 451 452 <p> 453 With some extra knowledge about how to manipulate buffers we can already use them in more interesting ways. The further you get in OpenGL, the more useful these new buffer methods start to become. In the <a href="https://learnopengl.com/Advanced-OpenGL/Advanced-GLSL" target="_blank">next</a> chapter, where we'll discuss <def>uniform buffer objects</def>, we'll make good use of <fun><function id='90'>glBufferSubData</function></fun>. 454 </p> 455 456 </div> 457 458 </main> 459 </body> 460 </html>