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 clamp_viewport(struct gl_context *ctx, GLfloat *x, GLfloat *y,
  40                GLfloat *width, GLfloat *height)
  41 {
  42    /* clamp width and height to the implementation dependent range */
  43    *width  = MIN2(*width, (GLfloat) ctx->Const.MaxViewportWidth);
  44    *height = MIN2(*height, (GLfloat) ctx->Const.MaxViewportHeight);
  45
  46    /* The GL_ARB_viewport_array spec says:
  47     *
  48     *     "The location of the viewport's bottom-left corner, given by (x,y),
  49     *     are clamped to be within the implementation-dependent viewport
  50     *     bounds range.  The viewport bounds range [min, max] tuple may be
  51     *     determined by calling GetFloatv with the symbolic constant
  52     *     VIEWPORT_BOUNDS_RANGE (see section 6.1)."
  53     */
  54    if (ctx->Extensions.ARB_viewport_array ||
  55        (ctx->Extensions.OES_viewport_array &&
  56         _mesa_is_gles31(ctx))) {
  57       *x = CLAMP(*x,
  58                  ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  59       *y = CLAMP(*y,
  60                  ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  61    }
  62 }
  63
  64 static void
  65 set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
  66                        GLfloat x, GLfloat y,
  67                        GLfloat width, GLfloat height)
  68 {
  69    if (ctx->ViewportArray[idx].X == x &&
  70        ctx->ViewportArray[idx].Width == width &&
  71        ctx->ViewportArray[idx].Y == y &&
  72        ctx->ViewportArray[idx].Height == height)
  73       return;
  74
  75    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewViewport ? 0 : _NEW_VIEWPORT);
  76    ctx->NewDriverState |= ctx->DriverFlags.NewViewport;
  77
  78    ctx->ViewportArray[idx].X = x;
  79    ctx->ViewportArray[idx].Width = width;
  80    ctx->ViewportArray[idx].Y = y;
  81    ctx->ViewportArray[idx].Height = height;
  82 }
  83
  84 struct gl_viewport_inputs {
  85    GLfloat X, Y;                /**< position */
  86    GLfloat Width, Height;       /**< size */
  87 };
  88
  89 struct gl_depthrange_inputs {
  90    GLdouble Near, Far;          /**< Depth buffer range */
  91 };
  92
  93 static void
  94 viewport(struct gl_context *ctx, GLint x, GLint y, GLsizei width,
  95          GLsizei height)
  96 {
  97    /* Clamp the viewport to the implementation dependent values. */
  98    clamp_viewport(ctx, (GLfloat *)&x, (GLfloat *)&y,
  99                   (GLfloat *)&width, (GLfloat *)&height);
 100
 101    /* The GL_ARB_viewport_array spec says:
 102     *
 103     *     "Viewport sets the parameters for all viewports to the same values
 104     *     and is equivalent (assuming no errors are generated) to:
 105     *
 106     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 107     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
 108     *
 109     * Set all of the viewports supported by the implementation, but only
 110     * signal the driver once at the end.
 111     */
 112    for (unsigned i = 0; i < ctx->Const.MaxViewports; i++)
 113       set_viewport_no_notify(ctx, i, x, y, width, height);
 114
 115    if (ctx->Driver.Viewport)
 116       ctx->Driver.Viewport(ctx);
 117 }
 118
 119 /**
 120  * Set the viewport.
 121  * \sa Called via glViewport() or display list execution.
 122  *
 123  * Flushes the vertices and calls _mesa_set_viewport() with the given
 124  * parameters.
 125  */
 126 void GLAPIENTRY
 127 _mesa_Viewport_no_error(GLint x, GLint y, GLsizei width, GLsizei height)
 128 {
 129    GET_CURRENT_CONTEXT(ctx);
 130    viewport(ctx, x, y, width, height);
 131 }
 132
 133 void GLAPIENTRY
 134 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
 135 {
 136    GET_CURRENT_CONTEXT(ctx);
 137
 138    if (MESA_VERBOSE & VERBOSE_API)
 139       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
 140
 141    if (width < 0 || height < 0) {
 142       _mesa_error(ctx,  GL_INVALID_VALUE,
 143                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
 144       return;
 145    }
 146
 147    viewport(ctx, x, y, width, height);
 148 }
 149
 150
 151 /**
 152  * Set new viewport parameters and update derived state.
 153  * Usually called from _mesa_Viewport().
 154  *
 155  * \param ctx GL context.
 156  * \param idx    Index of the viewport to be updated.
 157  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 158  * \param width width of the viewport rectangle.
 159  * \param height height of the viewport rectangle.
 160  */
 161 void
 162 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLfloat x, GLfloat y,
 163                     GLfloat width, GLfloat height)
 164 {
 165    clamp_viewport(ctx, &x, &y, &width, &height);
 166    set_viewport_no_notify(ctx, idx, x, y, width, height);
 167
 168    if (ctx->Driver.Viewport)
 169       ctx->Driver.Viewport(ctx);
 170 }
 171
 172 static void
 173 viewport_array(struct gl_context *ctx, GLuint first, GLsizei count,
 174                struct gl_viewport_inputs *inputs)
 175 {
 176    for (GLsizei i = 0; i < count; i++) {
 177       clamp_viewport(ctx, &inputs[i].X, &inputs[i].Y,
 178                      &inputs[i].Width, &inputs[i].Height);
 179
 180       set_viewport_no_notify(ctx, i + first, inputs[i].X, inputs[i].Y,
 181                              inputs[i].Width, inputs[i].Height);
 182    }
 183
 184    if (ctx->Driver.Viewport)
 185       ctx->Driver.Viewport(ctx);
 186 }
 187
 188 void GLAPIENTRY
 189 _mesa_ViewportArrayv_no_error(GLuint first, GLsizei count, const GLfloat *v)
 190 {
 191    GET_CURRENT_CONTEXT(ctx);
 192
 193    struct gl_viewport_inputs *p = (struct gl_viewport_inputs *)v;
 194    viewport_array(ctx, first, count, p);
 195 }
 196
 197 void GLAPIENTRY
 198 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 199 {
 200    int i;
 201    struct gl_viewport_inputs *p = (struct gl_viewport_inputs *)v;
 202    GET_CURRENT_CONTEXT(ctx);
 203
 204    if (MESA_VERBOSE & VERBOSE_API)
 205       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);
 206
 207    if ((first + count) > ctx->Const.MaxViewports) {
 208       _mesa_error(ctx, GL_INVALID_VALUE,
 209                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
 210                   "(%d)",
 211                   first, count, ctx->Const.MaxViewports);
 212       return;
 213    }
 214
 215    /* Verify width & height */
 216    for (i = 0; i < count; i++) {
 217       if (p[i].Width < 0 || p[i].Height < 0) {
 218          _mesa_error(ctx, GL_INVALID_VALUE,
 219                      "glViewportArrayv: index (%d) width or height < 0 "
 220                      "(%f, %f)",
 221                      i + first, p[i].Width, p[i].Height);
 222          return;
 223       }
 224    }
 225
 226    viewport_array(ctx, first, count, p);
 227 }
 228
 229 static void
 230 viewport_indexed_err(struct gl_context *ctx, GLuint index, GLfloat x, GLfloat y,
 231                      GLfloat w, GLfloat h, const char *function)
 232 {
 233    if (MESA_VERBOSE & VERBOSE_API)
 234       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
 235                   function, index, x, y, w, h);
 236
 237    if (index >= ctx->Const.MaxViewports) {
 238       _mesa_error(ctx, GL_INVALID_VALUE,
 239                   "%s: index (%d) >= MaxViewports (%d)",
 240                   function, index, ctx->Const.MaxViewports);
 241       return;
 242    }
 243
 244    /* Verify width & height */
 245    if (w < 0 || h < 0) {
 246       _mesa_error(ctx, GL_INVALID_VALUE,
 247                   "%s: index (%d) width or height < 0 (%f, %f)",
 248                   function, index, w, h);
 249       return;
 250    }
 251
 252    _mesa_set_viewport(ctx, index, x, y, w, h);
 253 }
 254
 255 void GLAPIENTRY
 256 _mesa_ViewportIndexedf_no_error(GLuint index, GLfloat x, GLfloat y,
 257                                 GLfloat w, GLfloat h)
 258 {
 259    GET_CURRENT_CONTEXT(ctx);
 260    _mesa_set_viewport(ctx, index, x, y, w, h);
 261 }
 262
 263 void GLAPIENTRY
 264 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 265                        GLfloat w, GLfloat h)
 266 {
 267    GET_CURRENT_CONTEXT(ctx);
 268    viewport_indexed_err(ctx, index, x, y, w, h, "glViewportIndexedf");
 269 }
 270
 271 void GLAPIENTRY
 272 _mesa_ViewportIndexedfv_no_error(GLuint index, const GLfloat *v)
 273 {
 274    GET_CURRENT_CONTEXT(ctx);
 275    _mesa_set_viewport(ctx, index, v[0], v[1], v[2], v[3]);
 276 }
 277
 278 void GLAPIENTRY
 279 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 280 {
 281    GET_CURRENT_CONTEXT(ctx);
 282    viewport_indexed_err(ctx, index, v[0], v[1], v[2], v[3],
 283                         "glViewportIndexedfv");
 284 }
 285
 286 static void
 287 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 288                           GLclampd nearval, GLclampd farval)
 289 {
 290    if (ctx->ViewportArray[idx].Near == nearval &&
 291        ctx->ViewportArray[idx].Far == farval)
 292       return;
 293
 294    /* The depth range is needed by program state constants. */
 295    FLUSH_VERTICES(ctx, _NEW_VIEWPORT);
 296    ctx->NewDriverState |= ctx->DriverFlags.NewViewport;
 297
 298    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 299    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 300 }
 301
 302 void
 303 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 304                       GLclampd nearval, GLclampd farval)
 305 {
 306    set_depth_range_no_notify(ctx, idx, nearval, farval);
 307
 308    if (ctx->Driver.DepthRange)
 309       ctx->Driver.DepthRange(ctx);
 310 }
 311
 312 /**
 313  * Called by glDepthRange
 314  *
 315  * \param nearval  specifies the Z buffer value which should correspond to
 316  *                 the near clip plane
 317  * \param farval  specifies the Z buffer value which should correspond to
 318  *                the far clip plane
 319  */
 320 void GLAPIENTRY
 321 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 322 {
 323    unsigned i;
 324    GET_CURRENT_CONTEXT(ctx);
 325
 326    if (MESA_VERBOSE&VERBOSE_API)
 327       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 328
 329    /* The GL_ARB_viewport_array spec says:
 330     *
 331     *     "DepthRange sets the depth range for all viewports to the same
 332     *     values and is equivalent (assuming no errors are generated) to:
 333     *
 334     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 335     *         DepthRangeIndexed(i, n, f);"
 336     *
 337     * Set the depth range for all of the viewports supported by the
 338     * implementation, but only signal the driver once at the end.
 339     */
 340    for (i = 0; i < ctx->Const.MaxViewports; i++)
 341       set_depth_range_no_notify(ctx, i, nearval, farval);
 342
 343    if (ctx->Driver.DepthRange) {
 344       ctx->Driver.DepthRange(ctx);
 345    }
 346 }
 347
 348 void GLAPIENTRY
 349 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 350 {
 351    _mesa_DepthRange(nearval, farval);
 352 }
 353
 354 /**
 355  * Update a range DepthRange values
 356  *
 357  * \param first   starting array index
 358  * \param count   count of DepthRange items to update
 359  * \param v       pointer to memory containing
 360  *                GLclampd near and far clip-plane values
 361  */
 362 void GLAPIENTRY
 363 _mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
 364 {
 365    int i;
 366    const struct gl_depthrange_inputs *const p =
 367       (struct gl_depthrange_inputs *) v;
 368    GET_CURRENT_CONTEXT(ctx);
 369
 370    if (MESA_VERBOSE & VERBOSE_API)
 371       _mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);
 372
 373    if ((first + count) > ctx->Const.MaxViewports) {
 374       _mesa_error(ctx, GL_INVALID_VALUE,
 375                   "glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
 376                   first, count, ctx->Const.MaxViewports);
 377       return;
 378    }
 379
 380    for (i = 0; i < count; i++)
 381       set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);
 382
 383    if (ctx->Driver.DepthRange)
 384       ctx->Driver.DepthRange(ctx);
 385 }
 386
 387 void GLAPIENTRY
 388 _mesa_DepthRangeArrayfvOES(GLuint first, GLsizei count, const GLfloat *v)
 389 {
 390    int i;
 391    GET_CURRENT_CONTEXT(ctx);
 392
 393    if (MESA_VERBOSE & VERBOSE_API)
 394       _mesa_debug(ctx, "glDepthRangeArrayfv %d %d\n", first, count);
 395
 396    if ((first + count) > ctx->Const.MaxViewports) {
 397       _mesa_error(ctx, GL_INVALID_VALUE,
 398                   "glDepthRangeArrayfv: first (%d) + count (%d) >= MaxViewports (%d)",
 399                   first, count, ctx->Const.MaxViewports);
 400       return;
 401    }
 402
 403    for (i = 0; i < count; i++)
 404       set_depth_range_no_notify(ctx, i + first, v[i * 2], v[i * 2 + 1]);
 405
 406    if (ctx->Driver.DepthRange)
 407       ctx->Driver.DepthRange(ctx);
 408 }
 409
 410 /**
 411  * Update a single DepthRange
 412  *
 413  * \param index    array index to update
 414  * \param nearval  specifies the Z buffer value which should correspond to
 415  *                 the near clip plane
 416  * \param farval   specifies the Z buffer value which should correspond to
 417  *                 the far clip plane
 418  */
 419 void GLAPIENTRY
 420 _mesa_DepthRangeIndexed_no_error(GLuint index, GLclampd nearval,
 421                                  GLclampd farval)
 422 {
 423    GET_CURRENT_CONTEXT(ctx);
 424    _mesa_set_depth_range(ctx, index, nearval, farval);
 425 }
 426
 427
 428 void GLAPIENTRY
 429 _mesa_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
 430 {
 431    GET_CURRENT_CONTEXT(ctx);
 432
 433    if (MESA_VERBOSE & VERBOSE_API)
 434       _mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
 435                   index, nearval, farval);
 436
 437    if (index >= ctx->Const.MaxViewports) {
 438       _mesa_error(ctx, GL_INVALID_VALUE,
 439                   "glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
 440                   index, ctx->Const.MaxViewports);
 441       return;
 442    }
 443
 444    _mesa_set_depth_range(ctx, index, nearval, farval);
 445 }
 446
 447 void GLAPIENTRY
 448 _mesa_DepthRangeIndexedfOES(GLuint index, GLfloat nearval, GLfloat farval)
 449 {
 450    _mesa_DepthRangeIndexed(index, nearval, farval);
 451 }
 452
 453 /**
 454  * Initialize the context viewport attribute group.
 455  * \param ctx  the GL context.
 456  */
 457 void _mesa_init_viewport(struct gl_context *ctx)
 458 {
 459    unsigned i;
 460
 461    ctx->Transform.ClipOrigin = GL_LOWER_LEFT;
 462    ctx->Transform.ClipDepthMode = GL_NEGATIVE_ONE_TO_ONE;
 463
 464    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 465     * so just initialize all of them.
 466     */
 467    for (i = 0; i < MAX_VIEWPORTS; i++) {
 468       /* Viewport group */
 469       ctx->ViewportArray[i].X = 0;
 470       ctx->ViewportArray[i].Y = 0;
 471       ctx->ViewportArray[i].Width = 0;
 472       ctx->ViewportArray[i].Height = 0;
 473       ctx->ViewportArray[i].Near = 0.0;
 474       ctx->ViewportArray[i].Far = 1.0;
 475    }
 476 }
 477
 478
 479 static void
 480 clip_control(struct gl_context *ctx, GLenum origin, GLenum depth)
 481 {
 482    if (ctx->Transform.ClipOrigin == origin &&
 483        ctx->Transform.ClipDepthMode == depth)
 484       return;
 485
 486    /* Affects transform state and the viewport transform */
 487    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewClipControl ? 0 :
 488                   _NEW_TRANSFORM | _NEW_VIEWPORT);
 489    ctx->NewDriverState |= ctx->DriverFlags.NewClipControl;
 490
 491    if (ctx->Transform.ClipOrigin != origin) {
 492       ctx->Transform.ClipOrigin = origin;
 493
 494       /* Affects the winding order of the front face. */
 495       if (ctx->DriverFlags.NewPolygonState)
 496          ctx->NewDriverState |= ctx->DriverFlags.NewPolygonState;
 497       else
 498          ctx->NewState |= _NEW_POLYGON;
 499
 500       if (ctx->Driver.FrontFace)
 501          ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
 502    }
 503
 504    if (ctx->Transform.ClipDepthMode != depth) {
 505       ctx->Transform.ClipDepthMode = depth;
 506
 507       if (ctx->Driver.DepthRange)
 508          ctx->Driver.DepthRange(ctx);
 509    }
 510 }
 511
 512
 513 void GLAPIENTRY
 514 _mesa_ClipControl_no_error(GLenum origin, GLenum depth)
 515 {
 516    GET_CURRENT_CONTEXT(ctx);
 517    clip_control(ctx, origin, depth);
 518 }
 519
 520
 521 void GLAPIENTRY
 522 _mesa_ClipControl(GLenum origin, GLenum depth)
 523 {
 524    GET_CURRENT_CONTEXT(ctx);
 525
 526    if (MESA_VERBOSE & VERBOSE_API)
 527       _mesa_debug(ctx, "glClipControl(%s, %s)\n",
 528                   _mesa_enum_to_string(origin),
 529                   _mesa_enum_to_string(depth));
 530
 531    ASSERT_OUTSIDE_BEGIN_END(ctx);
 532
 533    if (!ctx->Extensions.ARB_clip_control) {
 534       _mesa_error(ctx, GL_INVALID_OPERATION, "glClipControl");
 535       return;
 536    }
 537
 538    if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
 539       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 540       return;
 541    }
 542
 543    if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
 544       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 545       return;
 546    }
 547
 548    clip_control(ctx, origin, depth);
 549 }
 550
 551 /**
 552  * Computes the scaling and the translation part of the
 553  * viewport transform matrix of the \param i-th viewport
 554  * and writes that into \param scale and \param translate.
 555  */
 556 void
 557 _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
 558                          float scale[3], float translate[3])
 559 {
 560    float x = ctx->ViewportArray[i].X;
 561    float y = ctx->ViewportArray[i].Y;
 562    float half_width = 0.5f * ctx->ViewportArray[i].Width;
 563    float half_height = 0.5f * ctx->ViewportArray[i].Height;
 564    double n = ctx->ViewportArray[i].Near;
 565    double f = ctx->ViewportArray[i].Far;
 566
 567    scale[0] = half_width;
 568    translate[0] = half_width + x;
 569    if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
 570       scale[1] = -half_height;
 571    } else {
 572       scale[1] = half_height;
 573    }
 574    translate[1] = half_height + y;
 575
 576    if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
 577       scale[2] = 0.5 * (f - n);
 578       translate[2] = 0.5 * (n + f);
 579    } else {
 580       scale[2] = f - n;
 581       translate[2] = n;
 582    }
 583 }