src/nogl/noGLES1.inc

   1 implementation
   2
   3   uses SDL2;
   4
   5   const
   6     GL_FLOAT = $1406;
   7     GL_VERTEX_ARRAY = $8074;
   8     GL_NORMAL_ARRAY = $8075;
   9     GL_COLOR_ARRAY = $8076;
  10     GL_TEXTURE_COORD_ARRAY = $8078;
  11     GL_TRIANGLES = $0004;
  12     GL_TEXTURE0 = $84C0;
  13     GL_INVALID_ENUM = $0500;
  14
  15   const
  16     ValPerVertex = 2;
  17     ValPerColor = 4;
  18     ValPerCoord = 2;
  19
  20   type
  21     TArrayFloat = array of GLfloat;
  22
  23     TCmds = record
  24       mode: GLenum;
  25       v, c, t: TArrayFloat;
  26     end;
  27
  28   var
  29     cmds: TCmds;
  30
  31   var
  32     extList: string = '';
  33
  34   var
  35     es_glVertexPointer: procedure (size: GLint; _type: GLenum; stride: GLsizei; pointer: PGLvoid); cdecl;
  36     es_glColorPointer: procedure (size: GLint; _type: GLenum; stride: GLsizei; pointer: PGLvoid); cdecl;
  37     es_glTexCoordPointer: procedure (size: GLint; _type: GLenum; stride: GLsizei; pointer: PGLvoid); cdecl;
  38     es_glEnableClientState: procedure (arr: GLenum); cdecl;
  39     es_glDisableClientState: procedure (arr: GLenum); cdecl;
  40     es_glDrawArrays: procedure (mode: GLenum; first: GLint; count: GLsizei); cdecl;
  41 //    es_glActiveTexture: procedure(texture: GLenum); cdecl;
  42 //    es_glClientActiveTexture: procedure(texture: GLenum); cdecl;
  43     es_glColor4f: procedure(red, green, blue, alpha: GLfloat); cdecl;
  44
  45     es_glEnable: procedure (cap: GLenum); cdecl;
  46     es_glDisable: procedure (cap: GLenum); cdecl;
  47     es_glIsEnabled: function (cap: GLenum): GLBoolean; cdecl;
  48     es_glGetString: function (name: GLenum): PChar; cdecl;
  49     es_glClearColor: procedure (red, green, blue, alpha: GLclampf); cdecl;
  50     es_glClear: procedure (mask: GLbitfield); cdecl;
  51     es_glAlphaFunc: procedure (func: GLenum; ref: GLclampf); cdecl;
  52     es_glBlendFunc: procedure (sfactor, dfactor: GLenum); cdecl;
  53     es_glPointSize: procedure (size: GLfloat); cdecl;
  54     es_glLineWidth: procedure (width: GLfloat); cdecl;
  55     es_glGetIntegerv: procedure (pname: GLenum; params: PGLint); cdecl;
  56     es_glFlush: procedure; cdecl;
  57     es_glFinish: procedure; cdecl;
  58
  59     es_glLoadIdentity: procedure; cdecl;
  60     es_glMatrixMode: procedure (mode: GLenum); cdecl;
  61     es_glLoadMatrixf: procedure (m: PGLfloat); cdecl;
  62     es_glPushMatrix: procedure; cdecl;
  63     es_glPopMatrix: procedure; cdecl;
  64     es_glTranslatef: procedure (x, y, z: GLfloat); cdecl;
  65     es_glRotatef: procedure (angle, x, y, z: GLfloat); cdecl;
  66     es_glScalef: procedure (x, y, z: GLfloat); cdecl;
  67
  68     es_glReadPixels: procedure (x, y: GLint; width, height: GLsizei; format,_type: GLenum; pixels: PGLvoid); cdecl;
  69
  70     es_glViewport: procedure (x, y: GLint; width, height: GLsizei); cdecl;
  71     es_glScissor: procedure (x, y: GLint; width, height: GLsizei); cdecl;
  72     es_glStencilMask: procedure (mask: GLuint); cdecl;
  73     es_glStencilFunc: procedure (func: GLenum; ref: GLint; mask: GLuint); cdecl;
  74     es_glStencilOp: procedure (fail, zfail, zpass: GLenum); cdecl;
  75     es_glColorMask: procedure (red: GLboolean; green: GLboolean; blue: GLboolean; alpha: GLboolean); cdecl;
  76
  77     es_glBindTexture: procedure (target: GLenum; texture: GLuint); cdecl;
  78     es_glGenTextures: procedure (n: GLsizei; textures: PGLuint); cdecl;
  79     es_glTexEnvi: procedure (target: GLenum; pname: GLenum; param: GLint); cdecl;
  80     es_glTexParameterf: procedure (target: GLenum; pname: GLenum; param: GLfloat); cdecl;
  81     es_glTexParameteri: procedure (target: GLenum; pname: GLenum; param: GLint); cdecl;
  82     es_glTexImage2D: procedure (target: GLenum; level, internalformat: GLint; width, height: GLsizei; border: GLint; format, _type:GLenum; pixels: PGLvoid); cdecl;
  83     es_glTexSubImage2D: procedure (target: GLenum; level: GLint; xoffset, yoffset: GLint; width, height: GLsizei; format, _type: GLenum; pixels: PGLvoid); cdecl;
  84     es_glDeleteTextures: procedure (n: GLsizei; textures: PGLuint); cdecl;
  85
  86     es_glGenFramebuffers: procedure (n: GLsizei; framebuffers: PGLuint); cdecl;
  87     es_glBindFramebuffer: procedure (target: GLenum; framebuffer: GLuint); cdecl;
  88     es_glFramebufferTexture2D: procedure (target, attachment, textarget: GLenum; texture: GLuint; level: GLint); cdecl;
  89     es_glFramebufferRenderbuffer: procedure (target, attachment, rbotarget: GLenum; rbo: GLuint); cdecl;
  90     es_glCheckFramebufferStatus: function (framebuffer: GLuint): GLenum; cdecl;
  91     es_glDeleteFramebuffers: procedure (n: GLsizei; const framebuffers: PGLuint); cdecl;
  92
  93     es_glGenRenderbuffers: procedure (n: GLsizei; framebuffers: PGLuint); cdecl;
  94     es_glBindRenderbuffer: procedure (target: GLenum; renderbuffer: GLuint); cdecl;
  95     es_glRenderbufferStorage: procedure (target, internalformat: GLenum; w, h: GLsizei); cdecl;
  96     es_glDeleteRenderbuffers: procedure (n: GLsizei; const renderbuffers: PGLuint); cdecl;
  97
  98   procedure glEnable(cap: GLenum);
  99   begin
 100     es_glEnable(cap);
 101   end;
 102
 103   procedure glDisable(cap: GLenum);
 104   begin
 105     es_glDisable(cap);
 106   end;
 107
 108   function glIsEnabled(cap: GLenum): GLboolean;
 109   begin
 110     result := es_glIsEnabled(cap);
 111   end;
 112
 113   function glGetString(name: GLenum): PChar;
 114   begin
 115     result := es_glGetString(name);
 116   end;
 117
 118   procedure glClearColor(red, green, blue, alpha: GLclampf);
 119   begin
 120     es_glClearColor(red, green, blue, alpha);
 121   end;
 122
 123   procedure glClear(mask: GLbitfield);
 124   begin
 125     es_glClear(mask);
 126   end;
 127
 128   procedure glAlphaFunc(func: GLenum; ref: GLclampf);
 129   begin
 130     es_glAlphaFunc(func, ref);
 131   end;
 132
 133   procedure glBlendFunc(sfactor, dfactor: GLenum);
 134   begin
 135     es_glBlendFunc(sfactor, dfactor);
 136   end;
 137
 138   procedure glPointSize(size: GLfloat);
 139   begin
 140     es_glPointSize(size);
 141   end;
 142
 143   procedure glLineWidth(width: GLfloat);
 144   begin
 145     es_glLineWidth(width);
 146   end;
 147
 148   procedure glGetIntegerv(pname: GLenum; params: PGLint);
 149   begin
 150     es_glGetIntegerv(pname, params);
 151   end;
 152
 153   procedure glFlush;
 154   begin
 155     es_glFlush;
 156   end;
 157
 158   procedure glFinish;
 159   begin
 160     es_glFinish;
 161   end;
 162
 163
 164
 165
 166
 167   procedure glBegin(mode: GLenum);
 168   begin
 169     assert(cmds.mode = GL_INVALID_ENUM);
 170     assert((mode = GL_POINTS) or (mode = GL_LINES) or (mode = GL_QUADS));
 171     cmds.mode := mode;
 172     SetLength(cmds.v, 0);
 173     SetLength(cmds.c, 0);
 174     SetLength(cmds.t, 0);
 175   end;
 176
 177   procedure glEnd;
 178   begin
 179     assert(cmds.mode <> GL_INVALID_ENUM);
 180     assert(Length(cmds.v) mod ValPerVertex = 0);
 181     assert(Length(cmds.c) mod ValPerColor = 0);
 182     assert(Length(cmds.t) mod ValPerCoord = 0);
 183     if Length(cmds.c) <> 0 then
 184       assert(Length(cmds.v) div ValPerVertex = Length(cmds.c) div ValPerColor);
 185     if Length(cmds.t) <> 0 then
 186       assert(Length(cmds.v) div ValPerVertex = Length(cmds.t) div ValPerCoord);
 187
 188     es_glVertexPointer(ValPerVertex, GL_FLOAT, 0, @cmds.v[0]);
 189     es_glColorPointer(ValPerColor, GL_FLOAT, 0, @cmds.c[0]);
 190     es_glTexCoordPointer(ValPerCoord, GL_FLOAT, 0, @cmds.t[0]);
 191     es_glEnableClientState(GL_VERTEX_ARRAY);
 192     es_glEnableClientState(GL_COLOR_ARRAY);
 193     es_glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 194     es_glDisableClientState(GL_NORMAL_ARRAY);
 195
 196     if Length(cmds.c) = 0 then
 197       es_glDisableClientState(GL_COLOR_ARRAY);
 198     if Length(cmds.t) = 0 then
 199       es_glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 200
 201     if cmds.mode = GL_QUADS then
 202       es_glDrawArrays(GL_TRIANGLES, 0, Length(cmds.v) div ValPerVertex)
 203     else
 204       es_glDrawArrays(cmds.mode, 0, Length(cmds.v) div ValPerVertex);
 205
 206     SetLength(cmds.v, 0);
 207     SetLength(cmds.c, 0);
 208     SetLength(cmds.t, 0);
 209     cmds.mode := GL_INVALID_ENUM;
 210   end;
 211
 212 (* ---------- begin internals ---------- *)
 213
 214   procedure AddFloatRaw (var x: TArrayFloat; f: GLfloat);
 215     var i: Integer;
 216   begin
 217     i := Length(x);
 218     SetLength(x, i + 1);
 219     x[i] := f;
 220   end;
 221
 222   procedure AddFloatX (var x: TArrayFloat; v: array of GLfloat); inline;
 223     var i, j, vpx: Integer;
 224   begin
 225     i := Length(x);
 226     vpx := Length(v);
 227     if (cmds.mode = GL_QUADS) and (i div vpx mod 4 = 3) then
 228     begin
 229       for j := 0 to vpx - 1 do
 230         AddFloatRaw(x, x[i - 3*vpx + j]);
 231       for j := 0 to vpx - 1 do
 232         AddFloatRaw(x, x[i - 1*vpx + j]);
 233     end;
 234     for j := 0 to vpx - 1 do
 235       AddFloatRaw(x, v[j]);
 236   end;
 237
 238 (* ---------- end internals ---------- *)
 239
 240   procedure glVertex2f(x, y: GLfloat);
 241   begin
 242     AddFloatX(cmds.v, [x, y]);
 243   end;
 244
 245   procedure glVertex2i(x, y: GLint);
 246   begin
 247     AddFloatX(cmds.v, [x, y]);
 248   end;
 249
 250   procedure glColor4f(red, green, blue, alpha: GLfloat);
 251   begin
 252     if cmds.mode = GL_INVALID_ENUM then
 253       es_glColor4f(red, green, blue, alpha)
 254     else
 255       AddFloatX(cmds.c, [red, green, blue, alpha])
 256   end;
 257
 258   procedure glColor4ub(red, green, blue, alpha: GLubyte);
 259   begin
 260     glColor4f(red / 255, green / 255, blue / 255, alpha / 255)
 261   end;
 262
 263   procedure glColor3ub(red, green, blue: GLubyte);
 264   begin
 265     glColor4f(red / 255, green / 255, blue / 255, 255)
 266   end;
 267
 268   procedure glTexCoord2f(s, t: GLfloat);
 269   begin
 270     AddFloatX(cmds.t, [s, t]);
 271   end;
 272
 273   procedure glTexCoord2i(s, t: GLint);
 274   begin
 275     AddFloatX(cmds.t, [s, t]);
 276   end;
 277
 278
 279
 280
 281
 282
 283
 284   procedure glReadPixels(x, y: GLint; width, height: GLsizei; format, atype: GLenum; pixels: Pointer);
 285   begin
 286     es_glReadPixels(x, y, width, height, format, atype, pixels);
 287   end;
 288
 289
 290
 291
 292
 293
 294   procedure glLoadIdentity;
 295   begin
 296     es_glLoadIdentity;
 297   end;
 298
 299   procedure glMatrixMode(mode: GLenum);
 300   begin
 301     es_glMatrixMode(mode);
 302   end;
 303
 304   procedure glLoadMatrixd(const m: PGLdouble);
 305     var
 306       i: Integer;
 307       n: array [0..15] of GLfloat;
 308   begin
 309     for i := 0 to 15 do
 310       n[i] := m[i];
 311     es_glLoadMatrixf(@n[0]);
 312   end;
 313
 314   procedure glPushMatrix;
 315   begin
 316     es_glPushMatrix;
 317   end;
 318
 319   procedure glPopMatrix;
 320   begin
 321     es_glPopMatrix;
 322   end;
 323
 324   procedure glTranslatef(x, y, z: GLfloat);
 325   begin
 326     es_glTranslatef(x, y, z);
 327   end;
 328
 329   procedure glRotatef(angle, x, y, z: GLfloat);
 330   begin
 331     es_glRotatef(angle, x, y, z);
 332   end;
 333
 334   procedure glScalef(x, y, z: GLfloat);
 335   begin
 336     es_glScalef(x, y, z);
 337   end;
 338
 339
 340
 341
 342
 343
 344   procedure glViewport(x, y: GLint; width, height: GLsizei);
 345   begin
 346     es_glViewport(x, y, width, height);
 347   end;
 348
 349   procedure glScissor(x, y: GLint; width, height: GLsizei);
 350   begin
 351     es_glScissor(x, y, width, height);
 352   end;
 353
 354   procedure glStencilMask(mask: GLuint);
 355   begin
 356     es_glStencilMask(mask);
 357   end;
 358
 359   procedure glStencilFunc(func: GLenum; ref: GLint; mask: GLuint);
 360   begin
 361     es_glStencilFunc(func, ref, mask);
 362   end;
 363
 364   procedure glStencilOp(fail, zfail, zpass: GLenum);
 365   begin
 366     es_glStencilOp(fail, zfail, zpass);
 367   end;
 368
 369   procedure glColorMask(red, green, blue, alpha: GLboolean);
 370   begin
 371     es_glColorMask(red, green, blue, alpha);
 372   end;
 373
 374
 375
 376
 377
 378
 379   procedure glBindTexture(target: GLenum; texture: GLuint);
 380   begin
 381     es_glBindTexture(target, texture);
 382   end;
 383
 384   procedure glGenTextures(n: GLsizei; textures: PGLuint);
 385   begin
 386     es_glGenTextures(n, textures);
 387   end;
 388
 389   procedure glTexEnvi(target: GLenum; pname: GLenum; param: GLint);
 390   begin
 391     es_glTexEnvi(target, pname, param);
 392   end;
 393
 394   procedure glTexParameterf(target: GLenum; pname: GLenum; param: GLfloat);
 395   begin
 396     es_glTexParameterf(target, pname, param);
 397   end;
 398
 399   procedure glTexParameteri(target: GLenum; pname: GLenum; param: GLint);
 400   begin
 401     es_glTexParameteri(target, pname, param);
 402   end;
 403
 404   procedure glTexImage2D(target: GLenum; level, internalformat: GLint; width, height: GLsizei; border: GLint; format, atype: GLenum; const pixels: Pointer);
 405   begin
 406     es_glTexImage2D(target, level, internalformat, width, height, border, format, atype, pixels);
 407   end;
 408
 409   procedure glTexSubImage2D(target: GLenum; level, xoffset, yoffset: GLint; width, height: GLsizei; format, atype: GLenum; const pixels: Pointer);
 410   begin
 411     es_glTexSubImage2D(target, level, xoffset, yoffset, width, height, format, atype, pixels);
 412   end;
 413
 414   procedure glDeleteTextures(n: GLsizei; const textures: PGLuint);
 415   begin
 416     es_glDeleteTextures(n, textures);
 417   end;
 418
 419
 420
 421
 422
 423
 424   procedure glGenFramebuffers(n: GLsizei; framebuffers: PGLuint);
 425   begin
 426     es_glGenFramebuffers(n, framebuffers);
 427   end;
 428
 429   procedure glBindFramebuffer(target: GLenum; framebuffer: GLuint);
 430   begin
 431     es_glBindFramebuffer(target, framebuffer);
 432   end;
 433
 434   procedure glFramebufferTexture2D(target, attachment, textarget: GLenum; texture: GLuint; level: GLint);
 435   begin
 436     es_glFramebufferTexture2D(target, attachment, textarget, texture, level);
 437   end;
 438
 439   procedure glFramebufferRenderbuffer(target, attachment, rbotarget: GLenum; rbo: GLuint);
 440   begin
 441     es_glFramebufferRenderbuffer(target, attachment, rbotarget, rbo);
 442   end;
 443
 444   function glCheckFramebufferStatus(framebuffer: GLuint): GLenum;
 445   begin
 446     result := es_glCheckFramebufferStatus(framebuffer);
 447   end;
 448
 449   procedure glDeleteFramebuffers(n: GLsizei; const framebuffers: PGLuint);
 450   begin
 451     es_glDeleteFramebuffers(n, framebuffers);
 452   end;
 453
 454   procedure glGenRenderbuffers(n: GLsizei; renderbuffers: PGLuint);
 455   begin
 456     es_glGenRenderbuffers(n, renderbuffers);
 457   end;
 458
 459   procedure glBindRenderbuffer(target: GLenum; renderbuffer: GLuint);
 460   begin
 461     es_glBindRenderbuffer(target, renderbuffer);
 462   end;
 463
 464   procedure glRenderbufferStorage(target, internalformat: GLenum; w, h: GLsizei);
 465   begin
 466     es_glRenderbufferStorage(target, internalformat, w, h);
 467   end;
 468
 469   procedure glDeleteRenderbuffers(n: GLsizei; const renderbuffers: PGLuint);
 470   begin
 471     es_glDeleteRenderbuffers(n, renderbuffers);
 472   end;
 473
 474
 475
 476
 477
 478
 479   procedure nogl_Init;
 480   begin
 481     es_glVertexPointer := SDL_GL_GetProcAddress('glVertexPointer');
 482     es_glColorPointer := SDL_GL_GetProcAddress('glColorPointer');
 483     es_glTexCoordPointer := SDL_GL_GetProcAddress('glTexCoordPointer');
 484     es_glEnableClientState := SDL_GL_GetProcAddress('glEnableClientState');
 485     es_glDisableClientState := SDL_GL_GetProcAddress('glDisableClientState');
 486     es_glDrawArrays := SDL_GL_GetProcAddress('glDrawArrays');
 487 //    es_glActiveTexture := SDL_GL_GetProcAddress('glActiveTexture');
 488 //    es_glClientActiveTexture := SDL_GL_GetProcAddress('glClientActiveTexture');
 489     es_glColor4f := SDL_GL_GetProcAddress('glColor4f');
 490
 491     es_glEnable := SDL_GL_GetProcAddress('glEnable');
 492     es_glDisable := SDL_GL_GetProcAddress('glDisable');
 493     es_glIsEnabled := SDL_GL_GetProcAddress('glIsEnabled');
 494     es_glGetString := SDL_GL_GetProcAddress('glGetString');
 495     es_glClearColor := SDL_GL_GetProcAddress('glClearColor');
 496     es_glClear := SDL_GL_GetProcAddress('glClear');
 497     es_glAlphaFunc := SDL_GL_GetProcAddress('glAlphaFunc');
 498     es_glBlendFunc := SDL_GL_GetProcAddress('glBlendFunc');
 499     es_glPointSize := SDL_GL_GetProcAddress('glPointSize');
 500     es_glLineWidth := SDL_GL_GetProcAddress('glLineWidth');
 501     es_glGetIntegerv := SDL_GL_GetProcAddress('glGetIntegerv');
 502     es_glFlush := SDL_GL_GetProcAddress('glFlush');
 503     es_glFinish := SDL_GL_GetProcAddress('glFinish');
 504
 505     es_glLoadIdentity := SDL_GL_GetProcAddress('glLoadIdentity');
 506     es_glMatrixMode := SDL_GL_GetProcAddress('glMatrixMode');
 507     es_glLoadMatrixf := SDL_GL_GetProcAddress('glLoadMatrixf');
 508     es_glPushMatrix := SDL_GL_GetProcAddress('glPushMatrix');
 509     es_glPopMatrix := SDL_GL_GetProcAddress('glPopMatrix');
 510     es_glTranslatef := SDL_GL_GetProcAddress('glTranslatef');
 511     es_glRotatef := SDL_GL_GetProcAddress('glRotatef');
 512     es_glScalef := SDL_GL_GetProcAddress('glScalef');
 513
 514     es_glReadPixels := SDL_GL_GetProcAddress('glReadPixels');
 515
 516     es_glViewport := SDL_GL_GetProcAddress('glViewport');
 517     es_glScissor := SDL_GL_GetProcAddress('glScissor');
 518     es_glStencilMask := SDL_GL_GetProcAddress('glStencilMask');
 519     es_glStencilFunc := SDL_GL_GetProcAddress('glStencilFunc');
 520     es_glStencilOp := SDL_GL_GetProcAddress('glStencilOp');
 521     es_glColorMask := SDL_GL_GetProcAddress('glColorMask');
 522
 523     es_glBindTexture := SDL_GL_GetProcAddress('glBindTexture');
 524     es_glGenTextures := SDL_GL_GetProcAddress('glGenTextures');
 525     es_glTexEnvi := SDL_GL_GetProcAddress('glTexEnvi');
 526     es_glTexParameterf := SDL_GL_GetProcAddress('glTexParameterf');
 527     es_glTexParameteri := SDL_GL_GetProcAddress('glTexParameteri');
 528     es_glTexImage2D := SDL_GL_GetProcAddress('glTexImage2D');
 529     es_glTexSubImage2D := SDL_GL_GetProcAddress('glTexSubImage2D');
 530     es_glDeleteTextures := SDL_GL_GetProcAddress('glDeleteTextures');
 531
 532     es_glGenFramebuffers := SDL_GL_GetProcAddress('glGenFramebuffersOES');
 533     es_glBindFramebuffer := SDL_GL_GetProcAddress('glBindFramebufferOES');
 534     es_glFramebufferTexture2D := SDL_GL_GetProcAddress('glFramebufferTexture2DOES');;
 535     es_glFramebufferRenderbuffer := SDL_GL_GetProcAddress('glFramebufferRenderbufferOES');
 536     es_glCheckFramebufferStatus := SDL_GL_GetProcAddress('glCheckFramebufferStatusOES');
 537     es_glDeleteFramebuffers := SDL_GL_GetProcAddress('glDeleteFramebuffersOES');
 538
 539     es_glGenRenderbuffers := SDL_GL_GetProcAddress('glGenRenderbuffersOES');
 540     es_glBindRenderbuffer := SDL_GL_GetProcAddress('glBindRenderbufferOES');
 541     es_glRenderbufferStorage := SDL_GL_GetProcAddress('glRenderbufferStorageOES');
 542     es_glDeleteRenderbuffers := SDL_GL_GetProcAddress('glDeleteRenderbuffersOES');
 543
 544     cmds.mode := GL_INVALID_ENUM
 545   end;
 546
 547   procedure nogl_Quit;
 548   begin
 549     es_glVertexPointer := nil;
 550     es_glColorPointer := nil;
 551     es_glTexCoordPointer := nil;
 552     es_glEnableClientState := nil;
 553     es_glDisableClientState := nil;
 554     es_glDrawArrays := nil;
 555 //    es_glActiveTexture := nil;
 556 //    es_glClientActiveTexture := nil;
 557     es_glColor4f := nil;
 558
 559     es_glEnable := nil;
 560     es_glDisable := nil;
 561     es_glIsEnabled := nil;
 562     es_glGetString := nil;
 563     es_glClearColor := nil;
 564     es_glClear := nil;
 565     es_glAlphaFunc := nil;
 566     es_glBlendFunc := nil;
 567     es_glPointSize := nil;
 568     es_glLineWidth := nil;
 569     es_glGetIntegerv := nil;
 570     es_glFlush := nil;
 571     es_glFinish := nil;
 572
 573     es_glLoadIdentity := nil;
 574     es_glMatrixMode := nil;
 575     es_glLoadMatrixf := nil;
 576     es_glPushMatrix := nil;
 577     es_glPopMatrix := nil;
 578     es_glTranslatef := nil;
 579     es_glRotatef := nil;
 580     es_glScalef := nil;
 581
 582     es_glReadPixels := nil;
 583
 584     es_glViewport := nil;
 585     es_glScissor := nil;
 586     es_glStencilMask := nil;
 587     es_glStencilFunc := nil;
 588     es_glStencilOp := nil;
 589     es_glColorMask := nil;
 590
 591     es_glBindTexture := nil;
 592     es_glGenTextures := nil;
 593     es_glTexEnvi := nil;
 594     es_glTexParameterf := nil;
 595     es_glTexParameteri := nil;
 596     es_glTexImage2D := nil;
 597     es_glTexSubImage2D := nil;
 598     es_glDeleteTextures := nil;
 599
 600     es_glGenFramebuffers := nil;
 601     es_glBindFramebuffer := nil;
 602     es_glFramebufferTexture2D := nil;
 603     es_glFramebufferRenderbuffer := nil;
 604     es_glCheckFramebufferStatus := nil;
 605     es_glDeleteFramebuffers := nil;
 606
 607     es_glGenRenderbuffers := nil;
 608     es_glBindRenderbuffer := nil;
 609     es_glRenderbufferStorage := nil;
 610     es_glDeleteRenderbuffers := nil;
 611   end;
 612
 613   function nogl_ExtensionSupported(ext: string): Boolean;
 614   begin
 615     if (extList = '') and Assigned(es_glGetString) then
 616       extList := glGetString(GL_EXTENSIONS);
 617     result := pos(ext, extList) <> 0;
 618   end;
 619
 620 initialization