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