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 static void
  89 viewport(struct gl_context *ctx, GLint x, GLint y, GLsizei width,
  90          GLsizei height)
  91 {
  92    /* The GL_ARB_viewport_array spec says:
  93     *
  94     *     "Viewport sets the parameters for all viewports to the same values
  95     *     and is equivalent (assuming no errors are generated) to:
  96     *
  97     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
  98     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
  99     *
 100     * Set all of the viewports supported by the implementation, but only
 101     * signal the driver once at the end.
 102     */
 103    for (unsigned i = 0; i < ctx->Const.MaxViewports; i++)
 104       set_viewport_no_notify(ctx, i, x, y, width, height);
 105
 106    if (ctx->Driver.Viewport) {
 107       /* Many drivers will use this call to check for window size changes
 108        * and reallocate the z/stencil/accum/etc buffers if needed.
 109        */
 110       ctx->Driver.Viewport(ctx);
 111    }
 112 }
 113
 114 /**
 115  * Set the viewport.
 116  * \sa Called via glViewport() or display list execution.
 117  *
 118  * Flushes the vertices and calls _mesa_set_viewport() with the given
 119  * parameters.
 120  */
 121 void GLAPIENTRY
 122 _mesa_Viewport_no_error(GLint x, GLint y, GLsizei width, GLsizei height)
 123 {
 124    GET_CURRENT_CONTEXT(ctx);
 125    viewport(ctx, x, y, width, height);
 126 }
 127
 128 void GLAPIENTRY
 129 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
 130 {
 131    GET_CURRENT_CONTEXT(ctx);
 132
 133    if (MESA_VERBOSE & VERBOSE_API)
 134       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
 135
 136    if (width < 0 || height < 0) {
 137       _mesa_error(ctx,  GL_INVALID_VALUE,
 138                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
 139       return;
 140    }
 141
 142    viewport(ctx, x, y, width, height);
 143 }
 144
 145
 146 /**
 147  * Set new viewport parameters and update derived state.
 148  * Usually called from _mesa_Viewport().
 149  *
 150  * \param ctx GL context.
 151  * \param idx    Index of the viewport to be updated.
 152  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 153  * \param width width of the viewport rectangle.
 154  * \param height height of the viewport rectangle.
 155  */
 156 void
 157 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLfloat x, GLfloat y,
 158                     GLfloat width, GLfloat height)
 159 {
 160    set_viewport_no_notify(ctx, idx, x, y, width, height);
 161
 162    if (ctx->Driver.Viewport) {
 163       /* Many drivers will use this call to check for window size changes
 164        * and reallocate the z/stencil/accum/etc buffers if needed.
 165        */
 166       ctx->Driver.Viewport(ctx);
 167    }
 168 }
 169
 170 static void
 171 viewport_array(struct gl_context *ctx, GLuint first, GLsizei count,
 172                const struct gl_viewport_inputs *inputs)
 173 {
 174    for (GLsizei i = 0; i < count; i++) {
 175       set_viewport_no_notify(ctx, i + first, inputs[i].X, inputs[i].Y,
 176                              inputs[i].Width, inputs[i].Height);
 177    }
 178
 179    if (ctx->Driver.Viewport)
 180       ctx->Driver.Viewport(ctx);
 181 }
 182
 183 void GLAPIENTRY
 184 _mesa_ViewportArrayv_no_error(GLuint first, GLsizei count, const GLfloat *v)
 185 {
 186    GET_CURRENT_CONTEXT(ctx);
 187
 188    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *)v;
 189    viewport_array(ctx, first, count, p);
 190 }
 191
 192 void GLAPIENTRY
 193 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 194 {
 195    int i;
 196    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *) v;
 197    GET_CURRENT_CONTEXT(ctx);
 198
 199    if (MESA_VERBOSE & VERBOSE_API)
 200       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);
 201
 202    if ((first + count) > ctx->Const.MaxViewports) {
 203       _mesa_error(ctx, GL_INVALID_VALUE,
 204                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
 205                   "(%d)",
 206                   first, count, ctx->Const.MaxViewports);
 207       return;
 208    }
 209
 210    /* Verify width & height */
 211    for (i = 0; i < count; i++) {
 212       if (p[i].Width < 0 || p[i].Height < 0) {
 213          _mesa_error(ctx, GL_INVALID_VALUE,
 214                      "glViewportArrayv: index (%d) width or height < 0 "
 215                      "(%f, %f)",
 216                      i + first, p[i].Width, p[i].Height);
 217          return;
 218       }
 219    }
 220
 221    viewport_array(ctx, first, count, p);
 222 }
 223
 224 static void
 225 viewport_indexed_err(struct gl_context *ctx, GLuint index, GLfloat x, GLfloat y,
 226                      GLfloat w, GLfloat h, const char *function)
 227 {
 228    if (MESA_VERBOSE & VERBOSE_API)
 229       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
 230                   function, index, x, y, w, h);
 231
 232    if (index >= ctx->Const.MaxViewports) {
 233       _mesa_error(ctx, GL_INVALID_VALUE,
 234                   "%s: index (%d) >= MaxViewports (%d)",
 235                   function, index, ctx->Const.MaxViewports);
 236       return;
 237    }
 238
 239    /* Verify width & height */
 240    if (w < 0 || h < 0) {
 241       _mesa_error(ctx, GL_INVALID_VALUE,
 242                   "%s: index (%d) width or height < 0 (%f, %f)",
 243                   function, index, w, h);
 244       return;
 245    }
 246
 247    _mesa_set_viewport(ctx, index, x, y, w, h);
 248 }
 249
 250 void GLAPIENTRY
 251 _mesa_ViewportIndexedf_no_error(GLuint index, GLfloat x, GLfloat y,
 252                                 GLfloat w, GLfloat h)
 253 {
 254    GET_CURRENT_CONTEXT(ctx);
 255    _mesa_set_viewport(ctx, index, x, y, w, h);
 256 }
 257
 258 void GLAPIENTRY
 259 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 260                        GLfloat w, GLfloat h)
 261 {
 262    GET_CURRENT_CONTEXT(ctx);
 263    viewport_indexed_err(ctx, index, x, y, w, h, "glViewportIndexedf");
 264 }
 265
 266 void GLAPIENTRY
 267 _mesa_ViewportIndexedfv_no_error(GLuint index, const GLfloat *v)
 268 {
 269    GET_CURRENT_CONTEXT(ctx);
 270    _mesa_set_viewport(ctx, index, v[0], v[1], v[2], v[3]);
 271 }
 272
 273 void GLAPIENTRY
 274 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 275 {
 276    GET_CURRENT_CONTEXT(ctx);
 277    viewport_indexed_err(ctx, index, v[0], v[1], v[2], v[3],
 278                         "glViewportIndexedfv");
 279 }
 280
 281 static void
 282 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 283                           GLclampd nearval, GLclampd farval)
 284 {
 285    if (ctx->ViewportArray[idx].Near == nearval &&
 286        ctx->ViewportArray[idx].Far == farval)
 287       return;
 288
 289    /* The depth range is needed by program state constants. */
 290    FLUSH_VERTICES(ctx, _NEW_VIEWPORT);
 291    ctx->NewDriverState |= ctx->DriverFlags.NewViewport;
 292
 293    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 294    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 295 }
 296
 297 void
 298 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 299                       GLclampd nearval, GLclampd farval)
 300 {
 301    set_depth_range_no_notify(ctx, idx, nearval, farval);
 302
 303    if (ctx->Driver.DepthRange)
 304       ctx->Driver.DepthRange(ctx);
 305 }
 306
 307 /**
 308  * Called by glDepthRange
 309  *
 310  * \param nearval  specifies the Z buffer value which should correspond to
 311  *                 the near clip plane
 312  * \param farval  specifies the Z buffer value which should correspond to
 313  *                the far clip plane
 314  */
 315 void GLAPIENTRY
 316 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 317 {
 318    unsigned i;
 319    GET_CURRENT_CONTEXT(ctx);
 320
 321    if (MESA_VERBOSE&VERBOSE_API)
 322       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 323
 324    /* The GL_ARB_viewport_array spec says:
 325     *
 326     *     "DepthRange sets the depth range for all viewports to the same
 327     *     values and is equivalent (assuming no errors are generated) to:
 328     *
 329     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 330     *         DepthRangeIndexed(i, n, f);"
 331     *
 332     * Set the depth range for all of the viewports supported by the
 333     * implementation, but only signal the driver once at the end.
 334     */
 335    for (i = 0; i < ctx->Const.MaxViewports; i++)
 336       set_depth_range_no_notify(ctx, i, nearval, farval);
 337
 338    if (ctx->Driver.DepthRange) {
 339       ctx->Driver.DepthRange(ctx);
 340    }
 341 }
 342
 343 void GLAPIENTRY
 344 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 345 {
 346    _mesa_DepthRange(nearval, farval);
 347 }
 348
 349 /**
 350  * Update a range DepthRange values
 351  *
 352  * \param first   starting array index
 353  * \param count   count of DepthRange items to update
 354  * \param v       pointer to memory containing
 355  *                GLclampd near and far clip-plane values
 356  */
 357 void GLAPIENTRY
 358 _mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
 359 {
 360    int i;
 361    const struct gl_depthrange_inputs *const p =
 362       (struct gl_depthrange_inputs *) v;
 363    GET_CURRENT_CONTEXT(ctx);
 364
 365    if (MESA_VERBOSE & VERBOSE_API)
 366       _mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);
 367
 368    if ((first + count) > ctx->Const.MaxViewports) {
 369       _mesa_error(ctx, GL_INVALID_VALUE,
 370                   "glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
 371                   first, count, ctx->Const.MaxViewports);
 372       return;
 373    }
 374
 375    for (i = 0; i < count; i++)
 376       set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);
 377
 378    if (ctx->Driver.DepthRange)
 379       ctx->Driver.DepthRange(ctx);
 380 }
 381
 382 void GLAPIENTRY
 383 _mesa_DepthRangeArrayfvOES(GLuint first, GLsizei count, const GLfloat *v)
 384 {
 385    int i;
 386    GET_CURRENT_CONTEXT(ctx);
 387
 388    if (MESA_VERBOSE & VERBOSE_API)
 389       _mesa_debug(ctx, "glDepthRangeArrayfv %d %d\n", first, count);
 390
 391    if ((first + count) > ctx->Const.MaxViewports) {
 392       _mesa_error(ctx, GL_INVALID_VALUE,
 393                   "glDepthRangeArrayfv: first (%d) + count (%d) >= MaxViewports (%d)",
 394                   first, count, ctx->Const.MaxViewports);
 395       return;
 396    }
 397
 398    for (i = 0; i < count; i++)
 399       set_depth_range_no_notify(ctx, i + first, v[i * 2], v[i * 2 + 1]);
 400
 401    if (ctx->Driver.DepthRange)
 402       ctx->Driver.DepthRange(ctx);
 403 }
 404
 405 /**
 406  * Update a single DepthRange
 407  *
 408  * \param index    array index to update
 409  * \param nearval  specifies the Z buffer value which should correspond to
 410  *                 the near clip plane
 411  * \param farval   specifies the Z buffer value which should correspond to
 412  *                 the far clip plane
 413  */
 414 void GLAPIENTRY
 415 _mesa_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
 416 {
 417    GET_CURRENT_CONTEXT(ctx);
 418
 419    if (MESA_VERBOSE & VERBOSE_API)
 420       _mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
 421                   index, nearval, farval);
 422
 423    if (index >= ctx->Const.MaxViewports) {
 424       _mesa_error(ctx, GL_INVALID_VALUE,
 425                   "glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
 426                   index, ctx->Const.MaxViewports);
 427       return;
 428    }
 429
 430    _mesa_set_depth_range(ctx, index, nearval, farval);
 431 }
 432
 433 void GLAPIENTRY
 434 _mesa_DepthRangeIndexedfOES(GLuint index, GLfloat nearval, GLfloat farval)
 435 {
 436    _mesa_DepthRangeIndexed(index, nearval, farval);
 437 }
 438
 439 /**
 440  * Initialize the context viewport attribute group.
 441  * \param ctx  the GL context.
 442  */
 443 void _mesa_init_viewport(struct gl_context *ctx)
 444 {
 445    unsigned i;
 446
 447    ctx->Transform.ClipOrigin = GL_LOWER_LEFT;
 448    ctx->Transform.ClipDepthMode = GL_NEGATIVE_ONE_TO_ONE;
 449
 450    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 451     * so just initialize all of them.
 452     */
 453    for (i = 0; i < MAX_VIEWPORTS; i++) {
 454       /* Viewport group */
 455       ctx->ViewportArray[i].X = 0;
 456       ctx->ViewportArray[i].Y = 0;
 457       ctx->ViewportArray[i].Width = 0;
 458       ctx->ViewportArray[i].Height = 0;
 459       ctx->ViewportArray[i].Near = 0.0;
 460       ctx->ViewportArray[i].Far = 1.0;
 461    }
 462 }
 463
 464
 465 static void
 466 clip_control(struct gl_context *ctx, GLenum origin, GLenum depth)
 467 {
 468    if (ctx->Transform.ClipOrigin == origin &&
 469        ctx->Transform.ClipDepthMode == depth)
 470       return;
 471
 472    /* Affects transform state and the viewport transform */
 473    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewClipControl ? 0 :
 474                   _NEW_TRANSFORM | _NEW_VIEWPORT);
 475    ctx->NewDriverState |= ctx->DriverFlags.NewClipControl;
 476
 477    if (ctx->Transform.ClipOrigin != origin) {
 478       ctx->Transform.ClipOrigin = origin;
 479
 480       /* Affects the winding order of the front face. */
 481       if (ctx->DriverFlags.NewPolygonState)
 482          ctx->NewDriverState |= ctx->DriverFlags.NewPolygonState;
 483       else
 484          ctx->NewState |= _NEW_POLYGON;
 485
 486       if (ctx->Driver.FrontFace)
 487          ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
 488    }
 489
 490    if (ctx->Transform.ClipDepthMode != depth) {
 491       ctx->Transform.ClipDepthMode = depth;
 492
 493       if (ctx->Driver.DepthRange)
 494          ctx->Driver.DepthRange(ctx);
 495    }
 496 }
 497
 498
 499 void GLAPIENTRY
 500 _mesa_ClipControl_no_error(GLenum origin, GLenum depth)
 501 {
 502    GET_CURRENT_CONTEXT(ctx);
 503    clip_control(ctx, origin, depth);
 504 }
 505
 506
 507 void GLAPIENTRY
 508 _mesa_ClipControl(GLenum origin, GLenum depth)
 509 {
 510    GET_CURRENT_CONTEXT(ctx);
 511
 512    if (MESA_VERBOSE & VERBOSE_API)
 513       _mesa_debug(ctx, "glClipControl(%s, %s)\n",
 514                   _mesa_enum_to_string(origin),
 515                   _mesa_enum_to_string(depth));
 516
 517    ASSERT_OUTSIDE_BEGIN_END(ctx);
 518
 519    if (!ctx->Extensions.ARB_clip_control) {
 520       _mesa_error(ctx, GL_INVALID_OPERATION, "glClipControl");
 521       return;
 522    }
 523
 524    if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
 525       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 526       return;
 527    }
 528
 529    if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
 530       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 531       return;
 532    }
 533
 534    clip_control(ctx, origin, depth);
 535 }
 536
 537 /**
 538  * Computes the scaling and the translation part of the
 539  * viewport transform matrix of the \param i-th viewport
 540  * and writes that into \param scale and \param translate.
 541  */
 542 void
 543 _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
 544                          float scale[3], float translate[3])
 545 {
 546    float x = ctx->ViewportArray[i].X;
 547    float y = ctx->ViewportArray[i].Y;
 548    float half_width = 0.5f * ctx->ViewportArray[i].Width;
 549    float half_height = 0.5f * ctx->ViewportArray[i].Height;
 550    double n = ctx->ViewportArray[i].Near;
 551    double f = ctx->ViewportArray[i].Far;
 552
 553    scale[0] = half_width;
 554    translate[0] = half_width + x;
 555    if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
 556       scale[1] = -half_height;
 557    } else {
 558       scale[1] = half_height;
 559    }
 560    translate[1] = half_height + y;
 561
 562    if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
 563       scale[2] = 0.5 * (f - n);
 564       translate[2] = 0.5 * (n + f);
 565    } else {
 566       scale[2] = f - n;
 567       translate[2] = n;
 568    }
 569 }