src/mesa/main/buffers.c

   1 /* $Id: buffers.c,v 1.33 2002/03/16 00:53:15 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  4.1
   6  *
   7  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 #ifdef PC_HEADER
  29 #include "all.h"
  30 #else
  31 #include "glheader.h"
  32 #include "accum.h"
  33 #include "buffers.h"
  34 #include "colormac.h"
  35 #include "context.h"
  36 #include "depth.h"
  37 #include "enums.h"
  38 #include "macros.h"
  39 #include "mem.h"
  40 #include "stencil.h"
  41 #include "state.h"
  42 #include "mtypes.h"
  43 #endif
  44
  45
  46
  47 void
  48 _mesa_ClearIndex( GLfloat c )
  49 {
  50    GET_CURRENT_CONTEXT(ctx);
  51    ASSERT_OUTSIDE_BEGIN_END(ctx);
  52
  53    if (ctx->Color.ClearIndex == (GLuint) c)
  54       return;
  55
  56    FLUSH_VERTICES(ctx, _NEW_COLOR);
  57    ctx->Color.ClearIndex = (GLuint) c;
  58
  59    if (!ctx->Visual.rgbMode && ctx->Driver.ClearIndex) {
  60       /* it's OK to call glClearIndex in RGBA mode but it should be a NOP */
  61       (*ctx->Driver.ClearIndex)( ctx, ctx->Color.ClearIndex );
  62    }
  63 }
  64
  65
  66
  67 void
  68 _mesa_ClearColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
  69 {
  70    GLchan tmp[4];
  71    GET_CURRENT_CONTEXT(ctx);
  72    ASSERT_OUTSIDE_BEGIN_END(ctx);
  73
  74    UNCLAMPED_FLOAT_TO_CHAN(tmp[0], red);
  75    UNCLAMPED_FLOAT_TO_CHAN(tmp[1], green);
  76    UNCLAMPED_FLOAT_TO_CHAN(tmp[2], blue);
  77    UNCLAMPED_FLOAT_TO_CHAN(tmp[3], alpha);
  78
  79    if (TEST_EQ_4V(tmp, ctx->Color.ClearColor))
  80       return;
  81
  82    FLUSH_VERTICES(ctx, _NEW_COLOR);
  83    COPY_CHAN4(ctx->Color.ClearColor, tmp);
  84
  85    if (ctx->Visual.rgbMode && ctx->Driver.ClearColor) {
  86       /* it's OK to call glClearColor in CI mode but it should be a NOP */
  87       (*ctx->Driver.ClearColor)(ctx, ctx->Color.ClearColor);
  88    }
  89 }
  90
  91
  92
  93 void
  94 _mesa_Clear( GLbitfield mask )
  95 {
  96    GET_CURRENT_CONTEXT(ctx);
  97    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
  98
  99    if (MESA_VERBOSE & VERBOSE_API)
 100       fprintf(stderr, "glClear 0x%x\n", mask);
 101
 102    if (mask & ~(GL_COLOR_BUFFER_BIT |
 103                 GL_DEPTH_BUFFER_BIT |
 104                 GL_STENCIL_BUFFER_BIT |
 105                 GL_ACCUM_BUFFER_BIT)) {
 106       /* invalid bit set */
 107       _mesa_error( ctx, GL_INVALID_VALUE, "glClear(mask)");
 108       return;
 109    }
 110
 111    if (ctx->NewState) {
 112       _mesa_update_state( ctx );        /* update _Xmin, etc */
 113    }
 114
 115    if (ctx->RenderMode==GL_RENDER) {
 116       const GLint x = ctx->DrawBuffer->_Xmin;
 117       const GLint y = ctx->DrawBuffer->_Ymin;
 118       const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 119       const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 120       GLbitfield ddMask;
 121
 122       /* don't clear depth buffer if depth writing disabled */
 123       if (!ctx->Depth.Mask)
 124          CLEAR_BITS(mask, GL_DEPTH_BUFFER_BIT);
 125
 126       /* Build bitmask to send to driver Clear function */
 127       ddMask = mask & (GL_DEPTH_BUFFER_BIT |
 128                        GL_STENCIL_BUFFER_BIT |
 129                        GL_ACCUM_BUFFER_BIT);
 130       if (mask & GL_COLOR_BUFFER_BIT) {
 131          ddMask |= ctx->Color.DrawDestMask;
 132       }
 133
 134       ASSERT(ctx->Driver.Clear);
 135       ctx->Driver.Clear( ctx, ddMask, (GLboolean) !ctx->Scissor.Enabled,
 136                          x, y, width, height );
 137    }
 138 }
 139
 140
 141 void
 142 _mesa_DrawBuffer( GLenum mode )
 143 {
 144    GET_CURRENT_CONTEXT(ctx);
 145    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */
 146
 147
 148    if (MESA_VERBOSE & VERBOSE_API)
 149       fprintf(stderr, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(mode));
 150
 151    switch (mode) {
 152       case GL_AUX0:
 153       case GL_AUX1:
 154       case GL_AUX2:
 155       case GL_AUX3:
 156          /* AUX buffers not implemented in Mesa at this time */
 157          _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 158          return;
 159       case GL_RIGHT:
 160          if (!ctx->Visual.stereoMode) {
 161             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 162             return;}
 163          if (ctx->Visual.doubleBufferMode)
 164             ctx->Color.DrawDestMask = FRONT_RIGHT_BIT | BACK_RIGHT_BIT;
 165          else
 166             ctx->Color.DrawDestMask = FRONT_RIGHT_BIT;
 167          break;
 168       case GL_FRONT_RIGHT:
 169          if (!ctx->Visual.stereoMode) {
 170             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 171             return;
 172          }
 173          ctx->Color.DrawDestMask = FRONT_RIGHT_BIT;
 174          break;
 175       case GL_BACK_RIGHT:
 176          if (!ctx->Visual.stereoMode) {
 177             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 178             return;
 179          }
 180          if (!ctx->Visual.doubleBufferMode) {
 181             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 182             return;
 183          }
 184          ctx->Color.DrawDestMask = BACK_RIGHT_BIT;
 185          break;
 186       case GL_BACK_LEFT:
 187          if (!ctx->Visual.doubleBufferMode) {
 188             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 189             return;
 190          }
 191          ctx->Color.DrawDestMask = BACK_LEFT_BIT;
 192          break;
 193       case GL_FRONT_AND_BACK:
 194          if (!ctx->Visual.doubleBufferMode) {
 195             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 196             return;
 197          }
 198          if (ctx->Visual.stereoMode)
 199             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT
 200                                     | FRONT_RIGHT_BIT | BACK_RIGHT_BIT;
 201          else
 202             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT;
 203          break;
 204       case GL_BACK:
 205          if (!ctx->Visual.doubleBufferMode) {
 206             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 207             return;
 208          }
 209          if (ctx->Visual.stereoMode)
 210             ctx->Color.DrawDestMask = BACK_LEFT_BIT | BACK_RIGHT_BIT;
 211          else
 212             ctx->Color.DrawDestMask = BACK_LEFT_BIT;
 213          break;
 214       case GL_LEFT:
 215          /* never an error */
 216          if (ctx->Visual.doubleBufferMode)
 217             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT;
 218          else
 219             ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 220          break;
 221       case GL_FRONT_LEFT:
 222          /* never an error */
 223          ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 224          break;
 225       case GL_FRONT:
 226          /* never an error */
 227          if (ctx->Visual.stereoMode)
 228             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | FRONT_RIGHT_BIT;
 229          else
 230             ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 231          break;
 232       case GL_NONE:
 233          /* never an error */
 234          ctx->Color.DrawDestMask = 0;
 235          break;
 236       default:
 237          _mesa_error( ctx, GL_INVALID_ENUM, "glDrawBuffer" );
 238          return;
 239    }
 240
 241    /*
 242     * Make the dest buffer mode more precise if possible
 243     */
 244    if (mode == GL_LEFT && !ctx->Visual.doubleBufferMode)
 245       ctx->Color.DriverDrawBuffer = GL_FRONT_LEFT;
 246    else if (mode == GL_RIGHT && !ctx->Visual.doubleBufferMode)
 247       ctx->Color.DriverDrawBuffer = GL_FRONT_RIGHT;
 248    else if (mode == GL_FRONT && !ctx->Visual.stereoMode)
 249       ctx->Color.DriverDrawBuffer = GL_FRONT_LEFT;
 250    else if (mode == GL_BACK && !ctx->Visual.stereoMode)
 251       ctx->Color.DriverDrawBuffer = GL_BACK_LEFT;
 252    else
 253       ctx->Color.DriverDrawBuffer = mode;
 254
 255    /*
 256     * Set current alpha buffer pointer
 257     */
 258    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 259       if (ctx->Color.DriverDrawBuffer == GL_FRONT_LEFT)
 260          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->FrontLeftAlpha;
 261       else if (ctx->Color.DriverDrawBuffer == GL_BACK_LEFT)
 262          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->BackLeftAlpha;
 263       else if (ctx->Color.DriverDrawBuffer == GL_FRONT_RIGHT)
 264          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->FrontRightAlpha;
 265       else if (ctx->Color.DriverDrawBuffer == GL_BACK_RIGHT)
 266          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->BackRightAlpha;
 267    }
 268
 269    /*
 270     * If we get here there can't have been an error.
 271     * Now see if device driver can implement the drawing to the target
 272     * buffer(s).  The driver may not be able to do GL_FRONT_AND_BACK mode
 273     * for example.  We'll take care of that in the core code by looping
 274     * over the individual buffers.
 275     */
 276    ASSERT(ctx->Driver.SetDrawBuffer);
 277    if ( (*ctx->Driver.SetDrawBuffer)(ctx, ctx->Color.DriverDrawBuffer) ) {
 278       /* All OK, the driver will do all buffer writes */
 279       ctx->Color.MultiDrawBuffer = GL_FALSE;
 280    }
 281    else {
 282       /* We'll have to loop over the multiple draw buffer targets */
 283       ctx->Color.MultiDrawBuffer = GL_TRUE;
 284       /* Set drawing buffer to front for now */
 285       (void) (*ctx->Driver.SetDrawBuffer)(ctx, GL_FRONT_LEFT);
 286    }
 287
 288    ctx->Color.DrawBuffer = mode;
 289    ctx->NewState |= _NEW_COLOR;
 290 }
 291
 292
 293
 294 void
 295 _mesa_ReadBuffer( GLenum mode )
 296 {
 297    GET_CURRENT_CONTEXT(ctx);
 298    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 299
 300    if (MESA_VERBOSE & VERBOSE_API)
 301       fprintf(stderr, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(mode));
 302
 303    switch (mode) {
 304       case GL_AUX0:
 305       case GL_AUX1:
 306       case GL_AUX2:
 307       case GL_AUX3:
 308          /* AUX buffers not implemented in Mesa at this time */
 309          _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 310          return;
 311       case GL_LEFT:
 312       case GL_FRONT:
 313       case GL_FRONT_LEFT:
 314          /* Front-Left buffer, always exists */
 315          ctx->Pixel.DriverReadBuffer = GL_FRONT_LEFT;
 316          break;
 317       case GL_BACK:
 318       case GL_BACK_LEFT:
 319          /* Back-Left buffer, requires double buffering */
 320          if (!ctx->Visual.doubleBufferMode) {
 321             _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 322             return;
 323          }
 324          ctx->Pixel.DriverReadBuffer = GL_BACK_LEFT;
 325          break;
 326       case GL_FRONT_RIGHT:
 327       case GL_RIGHT:
 328          if (!ctx->Visual.stereoMode) {
 329             _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 330             return;
 331          }
 332          ctx->Pixel.DriverReadBuffer = GL_FRONT_RIGHT;
 333          break;
 334       case GL_BACK_RIGHT:
 335          if (!ctx->Visual.stereoMode || !ctx->Visual.doubleBufferMode) {
 336             _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 337             return;
 338          }
 339          ctx->Pixel.DriverReadBuffer = GL_BACK_RIGHT;
 340          break;
 341       default:
 342          _mesa_error( ctx, GL_INVALID_ENUM, "glReadBuffer" );
 343          return;
 344    }
 345
 346    ctx->Pixel.ReadBuffer = mode;
 347    ctx->NewState |= _NEW_PIXEL;
 348 }
 349
 350
 351 /*
 352  * GL_MESA_resize_buffers extension
 353  * When this function is called, we'll ask the window system how large
 354  * the current window is.  If it's not what we expect, we'll have to
 355  * resize/reallocate the software accum/stencil/depth/alpha buffers.
 356  */
 357 void
 358 _mesa_ResizeBuffersMESA( void )
 359 {
 360    GLcontext *ctx = _mesa_get_current_context();
 361
 362    if (MESA_VERBOSE & VERBOSE_API)
 363       fprintf(stderr, "glResizeBuffersMESA\n");
 364
 365    if (ctx) {
 366       ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 367
 368       if (ctx->DrawBuffer) {
 369          GLuint buf_width, buf_height;
 370          GLframebuffer *buffer = ctx->DrawBuffer;
 371
 372          /* ask device driver for size of output buffer */
 373          (*ctx->Driver.GetBufferSize)( buffer, &buf_width, &buf_height );
 374
 375          /* see if size of device driver's color buffer (window) has changed */
 376          if (buffer->Width == (GLint) buf_width &&
 377              buffer->Height == (GLint) buf_height)
 378             return; /* size is as expected */
 379
 380          buffer->Width = buf_width;
 381          buffer->Height = buf_height;
 382
 383          ctx->Driver.ResizeBuffers( buffer );
 384       }
 385
 386       if (ctx->ReadBuffer && ctx->ReadBuffer != ctx->DrawBuffer) {
 387          GLuint buf_width, buf_height;
 388          GLframebuffer *buffer = ctx->DrawBuffer;
 389
 390          /* ask device driver for size of output buffer */
 391          (*ctx->Driver.GetBufferSize)( buffer, &buf_width, &buf_height );
 392
 393          /* see if size of device driver's color buffer (window) has changed */
 394          if (buffer->Width == (GLint) buf_width &&
 395              buffer->Height == (GLint) buf_height)
 396             return; /* size is as expected */
 397
 398          buffer->Width = buf_width;
 399          buffer->Height = buf_height;
 400
 401          ctx->Driver.ResizeBuffers( buffer );
 402       }
 403
 404       ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
 405    }
 406 }
 407
 408
 409 void
 410 _mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
 411 {
 412    GET_CURRENT_CONTEXT(ctx);
 413    ASSERT_OUTSIDE_BEGIN_END(ctx);
 414
 415    if (width < 0 || height < 0) {
 416       _mesa_error( ctx, GL_INVALID_VALUE, "glScissor" );
 417       return;
 418    }
 419
 420    if (MESA_VERBOSE & VERBOSE_API)
 421       fprintf(stderr, "glScissor %d %d %d %d\n", x, y, width, height);
 422
 423    if (x == ctx->Scissor.X &&
 424        y == ctx->Scissor.Y &&
 425        width == ctx->Scissor.Width &&
 426        height == ctx->Scissor.Height)
 427       return;
 428
 429    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
 430    ctx->Scissor.X = x;
 431    ctx->Scissor.Y = y;
 432    ctx->Scissor.Width = width;
 433    ctx->Scissor.Height = height;
 434
 435    if (ctx->Driver.Scissor)
 436       ctx->Driver.Scissor( ctx, x, y, width, height );
 437 }
 438
 439
 440 /*
 441  * XXX move somewhere else someday?
 442  */
 443 void
 444 _mesa_SampleCoverageARB(GLclampf value, GLboolean invert)
 445 {
 446    GLcontext *ctx = _mesa_get_current_context();
 447
 448    if (!ctx->Extensions.ARB_multisample) {
 449       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleCoverageARB");
 450       return;
 451    }
 452
 453    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 454    ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0);
 455    ctx->Multisample.SampleCoverageInvert = invert;
 456    ctx->NewState |= _NEW_MULTISAMPLE;
 457 }
 458