src/opengl_vbo.c

   1 /*
   2  * See Licensing and Copyright notice in naev.h
   3  */
   4
   5 /**
   6  * @file opengl_vbo.c
   7  *
   8  * @brief Handles OpenGL vbos.
   9  */
  10
  11
  12 #include "opengl.h"
  13
  14 #include "naev.h"
  15
  16 #include "log.h"
  17
  18
  19 #define BUFFER_OFFSET(i) ((char *)NULL + (i)) /**< Taken from OpengL spec. */
  20
  21
  22 /**
  23  * @brief VBO types.
  24  */
  25 typedef enum gl_vboType_e {
  26    NGL_VBO_NULL, /**< No VBO type. */
  27    NGL_VBO_STREAM, /**< VBO streaming type. */
  28    NGL_VBO_STATIC /**< VBO static type. */
  29 } gl_vboType;
  30
  31
  32 /**
  33  * @brief Contains the VBO.
  34  */
  35 struct gl_vbo_s {
  36    GLuint id; /**< VBO ID. */
  37    gl_vboType type; /**< VBO type. */
  38    GLsizei size; /**< VBO size. */
  39    char* data; /**< VBO data. */
  40 };
  41
  42
  43 static int has_vbo = 0; /**< Whether or not has VBO. */
  44
  45
  46 /**
  47  * Prototypes.
  48  */
  49 static gl_vbo* gl_vboCreate( GLenum target, GLsizei size, void* data, GLenum usage );
  50
  51
  52 /**
  53  * @brief Initializes the OpenGL VBO subsystem.
  54  *
  55  *    @return 0 on success.
  56  */
  57 int gl_initVBO (void)
  58 {
  59    if (nglGenBuffers != NULL)
  60       has_vbo = 1;
  61
  62    return 0;
  63 }
  64
  65
  66 /**
  67  * @brief Exits the OpenGL VBO subsystem.
  68  */
  69 void gl_exitVBO (void)
  70 {
  71    has_vbo = 0;
  72 }
  73
  74
  75 /**
  76  * @brief Creates a VBO.
  77  *
  78  *    @param target Target to create to (usually GL_ARRAY_BUFFER).
  79  *    @param size Size of the buffer (in bytes).
  80  *    @param data The actual datat to use.
  81  *    @param usage Usage to use.
  82  *    @return ID of the vbo.
  83  */
  84 static gl_vbo* gl_vboCreate( GLenum target, GLsizei size, void* data, GLenum usage )
  85 {
  86    gl_vbo *vbo;
  87
  88    /* Allocate. */
  89    vbo = malloc( sizeof(gl_vbo) );
  90    memset( vbo, 0, sizeof(gl_vbo) );
  91
  92    /* General stuff. */
  93    vbo->size = size;
  94
  95    if (has_vbo) {
  96       /* Create the buffer. */
  97       nglGenBuffers( 1, &vbo->id );
  98
  99       /* Upload the data. */
 100       nglBindBuffer( target, vbo->id );
 101       nglBufferData( target, size, data, usage );
 102       nglBindBuffer( target, 0 );
 103    }
 104    else {
 105       vbo->size = size;
 106       vbo->data = malloc(size);
 107       if (data == NULL)
 108          memset( vbo->data, 0, size );
 109       else
 110          memcpy( vbo->data, data, size );
 111    }
 112
 113    /* Check for errors. */
 114    gl_checkErr();
 115
 116    return vbo;
 117 }
 118
 119
 120 /**
 121  * @brief Reloads new data or grows the size of the vbo.
 122  *
 123  *    @param vbo VBO to get new data of.
 124  *    @param size Size of new data.
 125  *    @param data New data.
 126  */
 127 void gl_vboData( gl_vbo *vbo, GLsizei size, void* data )
 128 {
 129    GLenum usage;
 130
 131    vbo->size = size;
 132
 133    if (has_vbo) {
 134       /* Get usage. */
 135       if (vbo->type == NGL_VBO_STREAM)
 136          usage = GL_STREAM_DRAW;
 137       else if (vbo->type == NGL_VBO_STATIC)
 138          usage = GL_STATIC_DRAW;
 139       else
 140          usage = GL_STREAM_DRAW;
 141
 142       /* Get new data. */
 143       nglBindBuffer( GL_ARRAY_BUFFER, vbo->id );
 144       nglBufferData( GL_ARRAY_BUFFER, size, data, usage );
 145    }
 146    else {
 147       /* Grow memory. */
 148       vbo->data = realloc( vbo->data, size );
 149       if (data == NULL)
 150          memset( vbo->data, 0, size );
 151       else
 152          memcpy( vbo->data, data, size );
 153    }
 154
 155    /* Check for errors. */
 156    gl_checkErr();
 157 }
 158
 159
 160 /**
 161  * @brief Loads some data into the VBO.
 162  *
 163  *    @param vbo VBO to load data into.
 164  *    @param offset Offset location of the data (in bytes).
 165  *    @param size Size of the data (in bytes).
 166  *    @param data Pointer to the data.
 167  */
 168 void gl_vboSubData( gl_vbo *vbo, GLint offset, GLsizei size, void* data )
 169 {
 170    if (has_vbo) {
 171       nglBindBuffer( GL_ARRAY_BUFFER, vbo->id );
 172       nglBufferSubData( GL_ARRAY_BUFFER, offset, size, data );
 173    }
 174    else {
 175       memcpy( &vbo->data[offset], data, size );
 176    }
 177
 178    /* Check for errors. */
 179    gl_checkErr();
 180 }
 181
 182
 183 /**
 184  * @brief Creates a stream vbo.
 185  *
 186  *    @param size Size of the stream vbo (multiply by sizeof(type)).
 187  *    @param data Data for the VBO.
 188  */
 189 gl_vbo* gl_vboCreateStream( GLsizei size, void* data )
 190 {
 191    gl_vbo *vbo;
 192
 193    vbo = gl_vboCreate( GL_ARRAY_BUFFER, size, data, GL_STREAM_DRAW );
 194    vbo->type = NGL_VBO_STREAM;
 195
 196    /* Check for errors. */
 197    gl_checkErr();
 198
 199    return vbo;
 200 }
 201
 202
 203 /**
 204  * @brief Creates a stream vbo.
 205  *
 206  *    @param size Size of the stream vbo (multiply by sizeof(type)).
 207  *    @param data Data for the VBO.
 208  */
 209 gl_vbo* gl_vboCreateStatic( GLsizei size, void* data )
 210 {
 211    gl_vbo *vbo;
 212
 213    vbo = gl_vboCreate( GL_ARRAY_BUFFER, size, data, GL_STATIC_DRAW );
 214    vbo->type = NGL_VBO_STATIC;
 215
 216    /* Check for errors. */
 217    gl_checkErr();
 218
 219    return vbo;
 220 }
 221
 222
 223 /**
 224  * @brief Maps a buffer.
 225  *
 226  *    @param vbo VBO to map.
 227  *    @return The data contained in the vbo.
 228  */
 229 void* gl_vboMap( gl_vbo *vbo )
 230 {
 231    if (has_vbo) {
 232       nglBindBuffer( GL_ARRAY_BUFFER, vbo->id );
 233       return nglMapBuffer( GL_ARRAY_BUFFER, GL_WRITE_ONLY );
 234    }
 235    else
 236       return vbo->data;
 237 }
 238
 239
 240 /**
 241  * @brief Unmaps a buffer.
 242  *
 243  *    @param vbo VBO to unmap.
 244  */
 245 void gl_vboUnmap( gl_vbo *vbo )
 246 {
 247    (void) vbo;
 248    if (has_vbo)
 249       nglUnmapBuffer( GL_ARRAY_BUFFER );
 250
 251    /* Check for errors. */
 252    gl_checkErr();
 253 }
 254
 255
 256 /**
 257  * @brief Activates a VBO.
 258  *
 259  *    @param vbo VBO to activate.
 260  *    @param Should be one of GL_COLOR_ARRAY, GL_VERTEX_ARRAY, or GL_TEXTURE_COORD_ARRAY.
 261  *    @param size Specifies components per point.
 262  *    @param type Type of data (usually GL_FLOAT).
 263  *    @param stride Offset between consecutive points.
 264  */
 265 void gl_vboActivate( gl_vbo *vbo, GLuint class, GLint size, GLenum type, GLsizei stride )
 266 {
 267    gl_vboActivateOffset( vbo, class, 0, size, type, stride );
 268 }
 269
 270
 271 /**
 272  * @brief Activates a VBO's offset.
 273  *
 274  *    @param vbo VBO to activate.
 275  *    @param class Should be one of GL_COLOR_ARRAY, GL_VERTEX_ARRAY,
 276  *           GL_TEXTURE_COORD_ARRAY, GL_TEXTURE0 or GL_TEXTURE1.
 277  *    @param offset Offset (in bytes).
 278  *    @param size Specifies components per point.
 279  *    @param type Type of data (usually GL_FLOAT).
 280  *    @param stride Offset between consecutive points.
 281  */
 282 void gl_vboActivateOffset( gl_vbo *vbo, GLuint class, GLuint offset,
 283       GLint size, GLenum type, GLsizei stride )
 284 {
 285    const GLvoid *pointer;
 286
 287    /* Set up. */
 288    if (has_vbo) {
 289       nglBindBuffer( GL_ARRAY_BUFFER, vbo->id );
 290       pointer = BUFFER_OFFSET(offset);
 291    }
 292    else
 293       pointer = &vbo->data[offset];
 294
 295    /* Class specific. */
 296    switch (class) {
 297       case GL_COLOR_ARRAY:
 298          glEnableClientState(class);
 299          glColorPointer( size, type, stride, pointer );
 300          break;
 301
 302       case GL_VERTEX_ARRAY:
 303          glEnableClientState(class);
 304          glVertexPointer( size, type, stride, pointer );
 305          break;
 306
 307       case GL_TEXTURE_COORD_ARRAY:
 308          glEnableClientState(class);
 309          glTexCoordPointer( size, type, stride, pointer );
 310          break;
 311
 312       case GL_TEXTURE0:
 313          nglClientActiveTexture( GL_TEXTURE0 );
 314          glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 315          glTexCoordPointer( size, type, stride, pointer );
 316          break;
 317
 318       case GL_TEXTURE1:
 319          nglClientActiveTexture( GL_TEXTURE1 );
 320          glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 321          glTexCoordPointer( size, type, stride, pointer );
 322          break;
 323
 324       default:
 325          WARN("Unknown VBO class.");
 326          break;
 327    }
 328
 329    /* Check for errors. */
 330    gl_checkErr();
 331 }
 332
 333
 334 /**
 335  * @brief Deactivates the vbo stuff.
 336  */
 337 void gl_vboDeactivate (void)
 338 {
 339    if (has_vbo)
 340       nglBindBuffer(GL_ARRAY_BUFFER, 0);
 341    glDisableClientState(GL_VERTEX_ARRAY);
 342    glDisableClientState(GL_COLOR_ARRAY);
 343    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 344    if (nglClientActiveTexture != NULL) {
 345       nglClientActiveTexture( GL_TEXTURE1 );
 346       glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 347       nglClientActiveTexture( GL_TEXTURE0 );
 348       glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 349    }
 350
 351    /* Check for errors. */
 352    gl_checkErr();
 353 }
 354
 355
 356 /**
 357  * @brief Destroys a VBO.
 358  *
 359  *    @param vbo VBO to destroy.
 360  */
 361 void gl_vboDestroy( gl_vbo *vbo )
 362 {
 363    if (has_vbo)
 364       /* Destroy VBO. */
 365       nglDeleteBuffers( 1, &vbo->id );
 366    else
 367       free(vbo->data);
 368
 369    /* Check for errors. */
 370    gl_checkErr();
 371
 372    /* Free memory. */
 373    free(vbo);
 374 }
 375
 376
 377 /**
 378  * @brief Checks to see if the VBOs are supported by HW.
 379  *
 380  *    @return 1 if VBOs are enabled and supported by HW.
 381  */
 382 int gl_vboIsHW (void)
 383 {
 384    return has_vbo;
 385 }
 386