src/mesa/main/viewport.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file viewport.c
  28  * glViewport and glDepthRange functions.
  29  */
  30
  31
  32 #include "context.h"
  33 #include "enums.h"
  34 #include "macros.h"
  35 #include "mtypes.h"
  36 #include "viewport.h"
  37
  38 static void
  39 set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
  40                        GLfloat x, GLfloat y,
  41                        GLfloat width, GLfloat height)
  42 {
  43    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewViewport ? 0 : _NEW_VIEWPORT);
  44    ctx->NewDriverState |= ctx->DriverFlags.NewViewport;
  45
  46    /* clamp width and height to the implementation dependent range */
  47    width  = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
  48    height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);
  49
  50    /* The GL_ARB_viewport_array spec says:
  51     *
  52     *     "The location of the viewport's bottom-left corner, given by (x,y),
  53     *     are clamped to be within the implementation-dependent viewport
  54     *     bounds range.  The viewport bounds range [min, max] tuple may be
  55     *     determined by calling GetFloatv with the symbolic constant
  56     *     VIEWPORT_BOUNDS_RANGE (see section 6.1)."
  57     */
  58    if (ctx->Extensions.ARB_viewport_array ||
  59        (ctx->Extensions.OES_viewport_array &&
  60         _mesa_is_gles31(ctx))) {
  61       x = CLAMP(x,
  62                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  63       y = CLAMP(y,
  64                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  65    }
  66
  67    if (ctx->ViewportArray[idx].X == x &&
  68        ctx->ViewportArray[idx].Width == width &&
  69        ctx->ViewportArray[idx].Y == y &&
  70        ctx->ViewportArray[idx].Height == height)
  71       return;
  72
  73    ctx->ViewportArray[idx].X = x;
  74    ctx->ViewportArray[idx].Width = width;
  75    ctx->ViewportArray[idx].Y = y;
  76    ctx->ViewportArray[idx].Height = height;
  77 }
  78
  79 struct gl_viewport_inputs {
  80    GLfloat X, Y;                /**< position */
  81    GLfloat Width, Height;       /**< size */
  82 };
  83
  84 struct gl_depthrange_inputs {
  85    GLdouble Near, Far;          /**< Depth buffer range */
  86 };
  87
  88 /**
  89  * Set the viewport.
  90  * \sa Called via glViewport() or display list execution.
  91  *
  92  * Flushes the vertices and calls _mesa_set_viewport() with the given
  93  * parameters.
  94  */
  95 void GLAPIENTRY
  96 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
  97 {
  98    unsigned i;
  99    GET_CURRENT_CONTEXT(ctx);
 100    FLUSH_VERTICES(ctx, 0);
 101
 102    if (MESA_VERBOSE & VERBOSE_API)
 103       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
 104
 105    if (width < 0 || height < 0) {
 106       _mesa_error(ctx,  GL_INVALID_VALUE,
 107                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
 108       return;
 109    }
 110
 111    /* The GL_ARB_viewport_array spec says:
 112     *
 113     *     "Viewport sets the parameters for all viewports to the same values
 114     *     and is equivalent (assuming no errors are generated) to:
 115     *
 116     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 117     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
 118     *
 119     * Set all of the viewports supported by the implementation, but only
 120     * signal the driver once at the end.
 121     */
 122    for (i = 0; i < ctx->Const.MaxViewports; i++)
 123       set_viewport_no_notify(ctx, i, x, y, width, height);
 124
 125    if (ctx->Driver.Viewport) {
 126       /* Many drivers will use this call to check for window size changes
 127        * and reallocate the z/stencil/accum/etc buffers if needed.
 128        */
 129       ctx->Driver.Viewport(ctx);
 130    }
 131 }
 132
 133
 134 /**
 135  * Set new viewport parameters and update derived state.
 136  * Usually called from _mesa_Viewport().
 137  *
 138  * \param ctx GL context.
 139  * \param idx    Index of the viewport to be updated.
 140  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 141  * \param width width of the viewport rectangle.
 142  * \param height height of the viewport rectangle.
 143  */
 144 void
 145 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLfloat x, GLfloat y,
 146                     GLfloat width, GLfloat height)
 147 {
 148    set_viewport_no_notify(ctx, idx, x, y, width, height);
 149
 150    if (ctx->Driver.Viewport) {
 151       /* Many drivers will use this call to check for window size changes
 152        * and reallocate the z/stencil/accum/etc buffers if needed.
 153        */
 154       ctx->Driver.Viewport(ctx);
 155    }
 156 }
 157
 158 static void
 159 viewport_array(struct gl_context *ctx, GLuint first, GLsizei count,
 160                const struct gl_viewport_inputs *inputs)
 161 {
 162    for (GLsizei i = 0; i < count; i++) {
 163       set_viewport_no_notify(ctx, i + first, inputs[i].X, inputs[i].Y,
 164                              inputs[i].Width, inputs[i].Height);
 165    }
 166
 167    if (ctx->Driver.Viewport)
 168       ctx->Driver.Viewport(ctx);
 169 }
 170
 171 void GLAPIENTRY
 172 _mesa_ViewportArrayv_no_error(GLuint first, GLsizei count, const GLfloat *v)
 173 {
 174    GET_CURRENT_CONTEXT(ctx);
 175
 176    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *)v;
 177    viewport_array(ctx, first, count, p);
 178 }
 179
 180 void GLAPIENTRY
 181 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 182 {
 183    int i;
 184    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *) v;
 185    GET_CURRENT_CONTEXT(ctx);
 186
 187    if (MESA_VERBOSE & VERBOSE_API)
 188       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);
 189
 190    if ((first + count) > ctx->Const.MaxViewports) {
 191       _mesa_error(ctx, GL_INVALID_VALUE,
 192                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
 193                   "(%d)",
 194                   first, count, ctx->Const.MaxViewports);
 195       return;
 196    }
 197
 198    /* Verify width & height */
 199    for (i = 0; i < count; i++) {
 200       if (p[i].Width < 0 || p[i].Height < 0) {
 201          _mesa_error(ctx, GL_INVALID_VALUE,
 202                      "glViewportArrayv: index (%d) width or height < 0 "
 203                      "(%f, %f)",
 204                      i + first, p[i].Width, p[i].Height);
 205          return;
 206       }
 207    }
 208
 209    viewport_array(ctx, first, count, p);
 210 }
 211
 212 static void
 213 viewport_indexed_err(struct gl_context *ctx, GLuint index, GLfloat x, GLfloat y,
 214                      GLfloat w, GLfloat h, const char *function)
 215 {
 216    if (MESA_VERBOSE & VERBOSE_API)
 217       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
 218                   function, index, x, y, w, h);
 219
 220    if (index >= ctx->Const.MaxViewports) {
 221       _mesa_error(ctx, GL_INVALID_VALUE,
 222                   "%s: index (%d) >= MaxViewports (%d)",
 223                   function, index, ctx->Const.MaxViewports);
 224       return;
 225    }
 226
 227    /* Verify width & height */
 228    if (w < 0 || h < 0) {
 229       _mesa_error(ctx, GL_INVALID_VALUE,
 230                   "%s: index (%d) width or height < 0 (%f, %f)",
 231                   function, index, w, h);
 232       return;
 233    }
 234
 235    _mesa_set_viewport(ctx, index, x, y, w, h);
 236 }
 237
 238 void GLAPIENTRY
 239 _mesa_ViewportIndexedf_no_error(GLuint index, GLfloat x, GLfloat y,
 240                                 GLfloat w, GLfloat h)
 241 {
 242    GET_CURRENT_CONTEXT(ctx);
 243    _mesa_set_viewport(ctx, index, x, y, w, h);
 244 }
 245
 246 void GLAPIENTRY
 247 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 248                        GLfloat w, GLfloat h)
 249 {
 250    GET_CURRENT_CONTEXT(ctx);
 251    viewport_indexed_err(ctx, index, x, y, w, h, "glViewportIndexedf");
 252 }
 253
 254 void GLAPIENTRY
 255 _mesa_ViewportIndexedfv_no_error(GLuint index, const GLfloat *v)
 256 {
 257    GET_CURRENT_CONTEXT(ctx);
 258    _mesa_set_viewport(ctx, index, v[0], v[1], v[2], v[3]);
 259 }
 260
 261 void GLAPIENTRY
 262 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 263 {
 264    GET_CURRENT_CONTEXT(ctx);
 265    viewport_indexed_err(ctx, index, v[0], v[1], v[2], v[3],
 266                         "glViewportIndexedfv");
 267 }
 268
 269 static void
 270 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 271                           GLclampd nearval, GLclampd farval)
 272 {
 273    if (ctx->ViewportArray[idx].Near == nearval &&
 274        ctx->ViewportArray[idx].Far == farval)
 275       return;
 276
 277    /* The depth range is needed by program state constants. */
 278    FLUSH_VERTICES(ctx, _NEW_VIEWPORT);
 279    ctx->NewDriverState |= ctx->DriverFlags.NewViewport;
 280
 281    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 282    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 283 }
 284
 285 void
 286 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 287                       GLclampd nearval, GLclampd farval)
 288 {
 289    set_depth_range_no_notify(ctx, idx, nearval, farval);
 290
 291    if (ctx->Driver.DepthRange)
 292       ctx->Driver.DepthRange(ctx);
 293 }
 294
 295 /**
 296  * Called by glDepthRange
 297  *
 298  * \param nearval  specifies the Z buffer value which should correspond to
 299  *                 the near clip plane
 300  * \param farval  specifies the Z buffer value which should correspond to
 301  *                the far clip plane
 302  */
 303 void GLAPIENTRY
 304 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 305 {
 306    unsigned i;
 307    GET_CURRENT_CONTEXT(ctx);
 308
 309    FLUSH_VERTICES(ctx, 0);
 310
 311    if (MESA_VERBOSE&VERBOSE_API)
 312       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 313
 314    /* The GL_ARB_viewport_array spec says:
 315     *
 316     *     "DepthRange sets the depth range for all viewports to the same
 317     *     values and is equivalent (assuming no errors are generated) to:
 318     *
 319     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 320     *         DepthRangeIndexed(i, n, f);"
 321     *
 322     * Set the depth range for all of the viewports supported by the
 323     * implementation, but only signal the driver once at the end.
 324     */
 325    for (i = 0; i < ctx->Const.MaxViewports; i++)
 326       set_depth_range_no_notify(ctx, i, nearval, farval);
 327
 328    if (ctx->Driver.DepthRange) {
 329       ctx->Driver.DepthRange(ctx);
 330    }
 331 }
 332
 333 void GLAPIENTRY
 334 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 335 {
 336    _mesa_DepthRange(nearval, farval);
 337 }
 338
 339 /**
 340  * Update a range DepthRange values
 341  *
 342  * \param first   starting array index
 343  * \param count   count of DepthRange items to update
 344  * \param v       pointer to memory containing
 345  *                GLclampd near and far clip-plane values
 346  */
 347 void GLAPIENTRY
 348 _mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
 349 {
 350    int i;
 351    const struct gl_depthrange_inputs *const p =
 352       (struct gl_depthrange_inputs *) v;
 353    GET_CURRENT_CONTEXT(ctx);
 354
 355    if (MESA_VERBOSE & VERBOSE_API)
 356       _mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);
 357
 358    if ((first + count) > ctx->Const.MaxViewports) {
 359       _mesa_error(ctx, GL_INVALID_VALUE,
 360                   "glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
 361                   first, count, ctx->Const.MaxViewports);
 362       return;
 363    }
 364
 365    for (i = 0; i < count; i++)
 366       set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);
 367
 368    if (ctx->Driver.DepthRange)
 369       ctx->Driver.DepthRange(ctx);
 370 }
 371
 372 void GLAPIENTRY
 373 _mesa_DepthRangeArrayfvOES(GLuint first, GLsizei count, const GLfloat *v)
 374 {
 375    int i;
 376    GET_CURRENT_CONTEXT(ctx);
 377
 378    if (MESA_VERBOSE & VERBOSE_API)
 379       _mesa_debug(ctx, "glDepthRangeArrayfv %d %d\n", first, count);
 380
 381    if ((first + count) > ctx->Const.MaxViewports) {
 382       _mesa_error(ctx, GL_INVALID_VALUE,
 383                   "glDepthRangeArrayfv: first (%d) + count (%d) >= MaxViewports (%d)",
 384                   first, count, ctx->Const.MaxViewports);
 385       return;
 386    }
 387
 388    for (i = 0; i < count; i++)
 389       set_depth_range_no_notify(ctx, i + first, v[i * 2], v[i * 2 + 1]);
 390
 391    if (ctx->Driver.DepthRange)
 392       ctx->Driver.DepthRange(ctx);
 393 }
 394
 395 /**
 396  * Update a single DepthRange
 397  *
 398  * \param index    array index to update
 399  * \param nearval  specifies the Z buffer value which should correspond to
 400  *                 the near clip plane
 401  * \param farval   specifies the Z buffer value which should correspond to
 402  *                 the far clip plane
 403  */
 404 void GLAPIENTRY
 405 _mesa_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
 406 {
 407    GET_CURRENT_CONTEXT(ctx);
 408
 409    if (MESA_VERBOSE & VERBOSE_API)
 410       _mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
 411                   index, nearval, farval);
 412
 413    if (index >= ctx->Const.MaxViewports) {
 414       _mesa_error(ctx, GL_INVALID_VALUE,
 415                   "glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
 416                   index, ctx->Const.MaxViewports);
 417       return;
 418    }
 419
 420    _mesa_set_depth_range(ctx, index, nearval, farval);
 421 }
 422
 423 void GLAPIENTRY
 424 _mesa_DepthRangeIndexedfOES(GLuint index, GLfloat nearval, GLfloat farval)
 425 {
 426    _mesa_DepthRangeIndexed(index, nearval, farval);
 427 }
 428
 429 /**
 430  * Initialize the context viewport attribute group.
 431  * \param ctx  the GL context.
 432  */
 433 void _mesa_init_viewport(struct gl_context *ctx)
 434 {
 435    unsigned i;
 436
 437    ctx->Transform.ClipOrigin = GL_LOWER_LEFT;
 438    ctx->Transform.ClipDepthMode = GL_NEGATIVE_ONE_TO_ONE;
 439
 440    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 441     * so just initialize all of them.
 442     */
 443    for (i = 0; i < MAX_VIEWPORTS; i++) {
 444       /* Viewport group */
 445       ctx->ViewportArray[i].X = 0;
 446       ctx->ViewportArray[i].Y = 0;
 447       ctx->ViewportArray[i].Width = 0;
 448       ctx->ViewportArray[i].Height = 0;
 449       ctx->ViewportArray[i].Near = 0.0;
 450       ctx->ViewportArray[i].Far = 1.0;
 451    }
 452 }
 453
 454
 455 static void
 456 clip_control(struct gl_context *ctx, GLenum origin, GLenum depth)
 457 {
 458    if (ctx->Transform.ClipOrigin == origin &&
 459        ctx->Transform.ClipDepthMode == depth)
 460       return;
 461
 462    /* Affects transform state and the viewport transform */
 463    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewClipControl ? 0 :
 464                   _NEW_TRANSFORM | _NEW_VIEWPORT);
 465    ctx->NewDriverState |= ctx->DriverFlags.NewClipControl;
 466
 467    if (ctx->Transform.ClipOrigin != origin) {
 468       ctx->Transform.ClipOrigin = origin;
 469
 470       /* Affects the winding order of the front face. */
 471       if (ctx->DriverFlags.NewPolygonState)
 472          ctx->NewDriverState |= ctx->DriverFlags.NewPolygonState;
 473       else
 474          ctx->NewState |= _NEW_POLYGON;
 475
 476       if (ctx->Driver.FrontFace)
 477          ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
 478    }
 479
 480    if (ctx->Transform.ClipDepthMode != depth) {
 481       ctx->Transform.ClipDepthMode = depth;
 482
 483       if (ctx->Driver.DepthRange)
 484          ctx->Driver.DepthRange(ctx);
 485    }
 486 }
 487
 488
 489 void GLAPIENTRY
 490 _mesa_ClipControl_no_error(GLenum origin, GLenum depth)
 491 {
 492    GET_CURRENT_CONTEXT(ctx);
 493    clip_control(ctx, origin, depth);
 494 }
 495
 496
 497 void GLAPIENTRY
 498 _mesa_ClipControl(GLenum origin, GLenum depth)
 499 {
 500    GET_CURRENT_CONTEXT(ctx);
 501
 502    if (MESA_VERBOSE & VERBOSE_API)
 503       _mesa_debug(ctx, "glClipControl(%s, %s)\n",
 504                   _mesa_enum_to_string(origin),
 505                   _mesa_enum_to_string(depth));
 506
 507    ASSERT_OUTSIDE_BEGIN_END(ctx);
 508
 509    if (!ctx->Extensions.ARB_clip_control) {
 510       _mesa_error(ctx, GL_INVALID_OPERATION, "glClipControl");
 511       return;
 512    }
 513
 514    if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
 515       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 516       return;
 517    }
 518
 519    if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
 520       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 521       return;
 522    }
 523
 524    clip_control(ctx, origin, depth);
 525 }
 526
 527 /**
 528  * Computes the scaling and the translation part of the
 529  * viewport transform matrix of the \param i-th viewport
 530  * and writes that into \param scale and \param translate.
 531  */
 532 void
 533 _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
 534                          float scale[3], float translate[3])
 535 {
 536    float x = ctx->ViewportArray[i].X;
 537    float y = ctx->ViewportArray[i].Y;
 538    float half_width = 0.5f * ctx->ViewportArray[i].Width;
 539    float half_height = 0.5f * ctx->ViewportArray[i].Height;
 540    double n = ctx->ViewportArray[i].Near;
 541    double f = ctx->ViewportArray[i].Far;
 542
 543    scale[0] = half_width;
 544    translate[0] = half_width + x;
 545    if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
 546       scale[1] = -half_height;
 547    } else {
 548       scale[1] = half_height;
 549    }
 550    translate[1] = half_height + y;
 551
 552    if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
 553       scale[2] = 0.5 * (f - n);
 554       translate[2] = 0.5 * (n + f);
 555    } else {
 556       scale[2] = f - n;
 557       translate[2] = n;
 558    }
 559 }