src/mesa/main/buffers.c

   1 /* $Id: buffers.c,v 1.31 2001/09/14 21:36:43 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2001  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 (ctx->NewState) {
 103       _mesa_update_state( ctx );        /* update _Xmin, etc */
 104    }
 105
 106    if (ctx->RenderMode==GL_RENDER) {
 107       const GLint x = ctx->DrawBuffer->_Xmin;
 108       const GLint y = ctx->DrawBuffer->_Ymin;
 109       const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 110       const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 111       GLbitfield ddMask;
 112
 113       /* don't clear depth buffer if depth writing disabled */
 114       if (!ctx->Depth.Mask)
 115          CLEAR_BITS(mask, GL_DEPTH_BUFFER_BIT);
 116
 117       /* Build bitmask to send to driver Clear function */
 118       ddMask = mask & (GL_DEPTH_BUFFER_BIT |
 119                        GL_STENCIL_BUFFER_BIT |
 120                        GL_ACCUM_BUFFER_BIT);
 121       if (mask & GL_COLOR_BUFFER_BIT) {
 122          ddMask |= ctx->Color.DrawDestMask;
 123       }
 124
 125       ASSERT(ctx->Driver.Clear);
 126       ctx->Driver.Clear( ctx, ddMask, (GLboolean) !ctx->Scissor.Enabled,
 127                          x, y, width, height );
 128    }
 129 }
 130
 131
 132 void
 133 _mesa_DrawBuffer( GLenum mode )
 134 {
 135    GET_CURRENT_CONTEXT(ctx);
 136    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */
 137
 138
 139    if (MESA_VERBOSE & VERBOSE_API)
 140       fprintf(stderr, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(mode));
 141
 142    switch (mode) {
 143       case GL_AUX0:
 144       case GL_AUX1:
 145       case GL_AUX2:
 146       case GL_AUX3:
 147          /* AUX buffers not implemented in Mesa at this time */
 148          _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 149          return;
 150       case GL_RIGHT:
 151          if (!ctx->Visual.stereoMode) {
 152             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 153             return;}
 154          if (ctx->Visual.doubleBufferMode)
 155             ctx->Color.DrawDestMask = FRONT_RIGHT_BIT | BACK_RIGHT_BIT;
 156          else
 157             ctx->Color.DrawDestMask = FRONT_RIGHT_BIT;
 158          break;
 159       case GL_FRONT_RIGHT:
 160          if (!ctx->Visual.stereoMode) {
 161             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 162             return;
 163          }
 164          ctx->Color.DrawDestMask = FRONT_RIGHT_BIT;
 165          break;
 166       case GL_BACK_RIGHT:
 167          if (!ctx->Visual.stereoMode) {
 168             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 169             return;
 170          }
 171          if (!ctx->Visual.doubleBufferMode) {
 172             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 173             return;
 174          }
 175          ctx->Color.DrawDestMask = BACK_RIGHT_BIT;
 176          break;
 177       case GL_BACK_LEFT:
 178          if (!ctx->Visual.doubleBufferMode) {
 179             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 180             return;
 181          }
 182          ctx->Color.DrawDestMask = BACK_LEFT_BIT;
 183          break;
 184       case GL_FRONT_AND_BACK:
 185          if (!ctx->Visual.doubleBufferMode) {
 186             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 187             return;
 188          }
 189          if (ctx->Visual.stereoMode)
 190             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT
 191                                     | FRONT_RIGHT_BIT | BACK_RIGHT_BIT;
 192          else
 193             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT;
 194          break;
 195       case GL_BACK:
 196          if (!ctx->Visual.doubleBufferMode) {
 197             _mesa_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 198             return;
 199          }
 200          if (ctx->Visual.stereoMode)
 201             ctx->Color.DrawDestMask = BACK_LEFT_BIT | BACK_RIGHT_BIT;
 202          else
 203             ctx->Color.DrawDestMask = BACK_LEFT_BIT;
 204          break;
 205       case GL_LEFT:
 206          /* never an error */
 207          if (ctx->Visual.doubleBufferMode)
 208             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT;
 209          else
 210             ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 211          break;
 212       case GL_FRONT_LEFT:
 213          /* never an error */
 214          ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 215          break;
 216       case GL_FRONT:
 217          /* never an error */
 218          if (ctx->Visual.stereoMode)
 219             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | FRONT_RIGHT_BIT;
 220          else
 221             ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 222          break;
 223       case GL_NONE:
 224          /* never an error */
 225          ctx->Color.DrawDestMask = 0;
 226          break;
 227       default:
 228          _mesa_error( ctx, GL_INVALID_ENUM, "glDrawBuffer" );
 229          return;
 230    }
 231
 232    /*
 233     * Make the dest buffer mode more precise if possible
 234     */
 235    if (mode == GL_LEFT && !ctx->Visual.doubleBufferMode)
 236       ctx->Color.DriverDrawBuffer = GL_FRONT_LEFT;
 237    else if (mode == GL_RIGHT && !ctx->Visual.doubleBufferMode)
 238       ctx->Color.DriverDrawBuffer = GL_FRONT_RIGHT;
 239    else if (mode == GL_FRONT && !ctx->Visual.stereoMode)
 240       ctx->Color.DriverDrawBuffer = GL_FRONT_LEFT;
 241    else if (mode == GL_BACK && !ctx->Visual.stereoMode)
 242       ctx->Color.DriverDrawBuffer = GL_BACK_LEFT;
 243    else
 244       ctx->Color.DriverDrawBuffer = mode;
 245
 246    /*
 247     * Set current alpha buffer pointer
 248     */
 249    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 250       if (ctx->Color.DriverDrawBuffer == GL_FRONT_LEFT)
 251          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->FrontLeftAlpha;
 252       else if (ctx->Color.DriverDrawBuffer == GL_BACK_LEFT)
 253          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->BackLeftAlpha;
 254       else if (ctx->Color.DriverDrawBuffer == GL_FRONT_RIGHT)
 255          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->FrontRightAlpha;
 256       else if (ctx->Color.DriverDrawBuffer == GL_BACK_RIGHT)
 257          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->BackRightAlpha;
 258    }
 259
 260    /*
 261     * If we get here there can't have been an error.
 262     * Now see if device driver can implement the drawing to the target
 263     * buffer(s).  The driver may not be able to do GL_FRONT_AND_BACK mode
 264     * for example.  We'll take care of that in the core code by looping
 265     * over the individual buffers.
 266     */
 267    ASSERT(ctx->Driver.SetDrawBuffer);
 268    if ( (*ctx->Driver.SetDrawBuffer)(ctx, ctx->Color.DriverDrawBuffer) ) {
 269       /* All OK, the driver will do all buffer writes */
 270       ctx->Color.MultiDrawBuffer = GL_FALSE;
 271    }
 272    else {
 273       /* We'll have to loop over the multiple draw buffer targets */
 274       ctx->Color.MultiDrawBuffer = GL_TRUE;
 275       /* Set drawing buffer to front for now */
 276       (void) (*ctx->Driver.SetDrawBuffer)(ctx, GL_FRONT_LEFT);
 277    }
 278
 279    ctx->Color.DrawBuffer = mode;
 280    ctx->NewState |= _NEW_COLOR;
 281 }
 282
 283
 284
 285 void
 286 _mesa_ReadBuffer( GLenum mode )
 287 {
 288    GET_CURRENT_CONTEXT(ctx);
 289    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 290
 291    if (MESA_VERBOSE & VERBOSE_API)
 292       fprintf(stderr, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(mode));
 293
 294    switch (mode) {
 295       case GL_AUX0:
 296       case GL_AUX1:
 297       case GL_AUX2:
 298       case GL_AUX3:
 299          /* AUX buffers not implemented in Mesa at this time */
 300          _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 301          return;
 302       case GL_LEFT:
 303       case GL_FRONT:
 304       case GL_FRONT_LEFT:
 305          /* Front-Left buffer, always exists */
 306          ctx->Pixel.DriverReadBuffer = GL_FRONT_LEFT;
 307          break;
 308       case GL_BACK:
 309       case GL_BACK_LEFT:
 310          /* Back-Left buffer, requires double buffering */
 311          if (!ctx->Visual.doubleBufferMode) {
 312             _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 313             return;
 314          }
 315          ctx->Pixel.DriverReadBuffer = GL_BACK_LEFT;
 316          break;
 317       case GL_FRONT_RIGHT:
 318       case GL_RIGHT:
 319          if (!ctx->Visual.stereoMode) {
 320             _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 321             return;
 322          }
 323          ctx->Pixel.DriverReadBuffer = GL_FRONT_RIGHT;
 324          break;
 325       case GL_BACK_RIGHT:
 326          if (!ctx->Visual.stereoMode || !ctx->Visual.doubleBufferMode) {
 327             _mesa_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 328             return;
 329          }
 330          ctx->Pixel.DriverReadBuffer = GL_BACK_RIGHT;
 331          break;
 332       default:
 333          _mesa_error( ctx, GL_INVALID_ENUM, "glReadBuffer" );
 334          return;
 335    }
 336
 337    ctx->Pixel.ReadBuffer = mode;
 338    ctx->NewState |= _NEW_PIXEL;
 339 }
 340
 341
 342 /*
 343  * GL_MESA_resize_buffers extension
 344  */
 345 void
 346 _mesa_ResizeBuffersMESA( void )
 347 {
 348    GLcontext *ctx = _mesa_get_current_context();
 349    GLuint buf_width, buf_height;
 350    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 351
 352
 353    if (MESA_VERBOSE & VERBOSE_API)
 354       fprintf(stderr, "glResizeBuffersMESA\n");
 355
 356    /* ask device driver for size of output buffer */
 357    (*ctx->Driver.GetBufferSize)( ctx, &buf_width, &buf_height );
 358
 359    /* see if size of device driver's color buffer (window) has changed */
 360    if (ctx->DrawBuffer->Width == (GLint) buf_width &&
 361        ctx->DrawBuffer->Height == (GLint) buf_height)
 362       return;
 363
 364    ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
 365
 366    /* save buffer size */
 367    ctx->DrawBuffer->Width = buf_width;
 368    ctx->DrawBuffer->Height = buf_height;
 369
 370    ctx->Driver.ResizeBuffersMESA( ctx );
 371 }
 372
 373
 374 void
 375 _mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
 376 {
 377    GET_CURRENT_CONTEXT(ctx);
 378    ASSERT_OUTSIDE_BEGIN_END(ctx);
 379
 380    if (width < 0 || height < 0) {
 381       _mesa_error( ctx, GL_INVALID_VALUE, "glScissor" );
 382       return;
 383    }
 384
 385    if (MESA_VERBOSE & VERBOSE_API)
 386       fprintf(stderr, "glScissor %d %d %d %d\n", x, y, width, height);
 387
 388    if (x == ctx->Scissor.X &&
 389        y == ctx->Scissor.Y &&
 390        width == ctx->Scissor.Width &&
 391        height == ctx->Scissor.Height)
 392       return;
 393
 394    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
 395    ctx->Scissor.X = x;
 396    ctx->Scissor.Y = y;
 397    ctx->Scissor.Width = width;
 398    ctx->Scissor.Height = height;
 399
 400    if (ctx->Driver.Scissor)
 401       ctx->Driver.Scissor( ctx, x, y, width, height );
 402 }
 403
 404
 405 /*
 406  * XXX move somewhere else someday?
 407  */
 408 void
 409 _mesa_SampleCoverageARB(GLclampf value, GLboolean invert)
 410 {
 411    GLcontext *ctx = _mesa_get_current_context();
 412
 413    if (!ctx->Extensions.ARB_multisample) {
 414       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleCoverageARB");
 415       return;
 416    }
 417
 418    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 419    ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0);
 420    ctx->Multisample.SampleCoverageInvert = invert;
 421    ctx->NewState |= _NEW_MULTISAMPLE;
 422 }
 423