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