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