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