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    double scale[3], translate[3];
  44
  45    /* clamp width and height to the implementation dependent range */
  46    width  = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
  47    height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);
  48
  49    /* The GL_ARB_viewport_array spec says:
  50     *
  51     *     "The location of the viewport's bottom-left corner, given by (x,y),
  52     *     are clamped to be within the implementation-dependent viewport
  53     *     bounds range.  The viewport bounds range [min, max] tuple may be
  54     *     determined by calling GetFloatv with the symbolic constant
  55     *     VIEWPORT_BOUNDS_RANGE (see section 6.1)."
  56     */
  57    if (ctx->Extensions.ARB_viewport_array) {
  58       x = CLAMP(x,
  59                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  60       y = CLAMP(y,
  61                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  62    }
  63
  64    if (ctx->ViewportArray[idx].X == x &&
  65        ctx->ViewportArray[idx].Width == width &&
  66        ctx->ViewportArray[idx].Y == y &&
  67        ctx->ViewportArray[idx].Height == height)
  68       return;
  69
  70    ctx->ViewportArray[idx].X = x;
  71    ctx->ViewportArray[idx].Width = width;
  72    ctx->ViewportArray[idx].Y = y;
  73    ctx->ViewportArray[idx].Height = height;
  74    ctx->NewState |= _NEW_VIEWPORT;
  75
  76 #if 1
  77    /* XXX remove this someday.  Currently the DRI drivers rely on
  78     * the WindowMap matrix being up to date in the driver's Viewport
  79     * and DepthRange functions.
  80     */
  81    _mesa_get_viewport_xform(ctx, idx, scale, translate);
  82    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
  83                          scale, translate, ctx->DrawBuffer->_DepthMaxF);
  84 #endif
  85 }
  86
  87 struct gl_viewport_inputs {
  88    GLfloat X, Y;                /**< position */
  89    GLfloat Width, Height;       /**< size */
  90 };
  91
  92 struct gl_depthrange_inputs {
  93    GLdouble Near, Far;          /**< Depth buffer range */
  94 };
  95
  96 /**
  97  * Set the viewport.
  98  * \sa Called via glViewport() or display list execution.
  99  *
 100  * Flushes the vertices and calls _mesa_set_viewport() with the given
 101  * parameters.
 102  */
 103 void GLAPIENTRY
 104 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
 105 {
 106    unsigned i;
 107    GET_CURRENT_CONTEXT(ctx);
 108    FLUSH_VERTICES(ctx, 0);
 109
 110    if (MESA_VERBOSE & VERBOSE_API)
 111       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
 112
 113    if (width < 0 || height < 0) {
 114       _mesa_error(ctx,  GL_INVALID_VALUE,
 115                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
 116       return;
 117    }
 118
 119    /* The GL_ARB_viewport_array spec says:
 120     *
 121     *     "Viewport sets the parameters for all viewports to the same values
 122     *     and is equivalent (assuming no errors are generated) to:
 123     *
 124     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 125     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
 126     *
 127     * Set all of the viewports supported by the implementation, but only
 128     * signal the driver once at the end.
 129     */
 130    for (i = 0; i < ctx->Const.MaxViewports; i++)
 131       set_viewport_no_notify(ctx, i, x, y, width, height);
 132
 133    if (ctx->Driver.Viewport) {
 134       /* Many drivers will use this call to check for window size changes
 135        * and reallocate the z/stencil/accum/etc buffers if needed.
 136        */
 137       ctx->Driver.Viewport(ctx);
 138    }
 139 }
 140
 141
 142 /**
 143  * Set new viewport parameters and update derived state (the _WindowMap
 144  * matrix).  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       /* Many drivers will use this call to check for window size changes
 160        * and reallocate the z/stencil/accum/etc buffers if needed.
 161        */
 162       ctx->Driver.Viewport(ctx);
 163    }
 164 }
 165
 166 void GLAPIENTRY
 167 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 168 {
 169    int i;
 170    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *) v;
 171    GET_CURRENT_CONTEXT(ctx);
 172
 173    if (MESA_VERBOSE & VERBOSE_API)
 174       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);
 175
 176    if ((first + count) > ctx->Const.MaxViewports) {
 177       _mesa_error(ctx, GL_INVALID_VALUE,
 178                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
 179                   "(%d)",
 180                   first, count, ctx->Const.MaxViewports);
 181       return;
 182    }
 183
 184    /* Verify width & height */
 185    for (i = 0; i < count; i++) {
 186       if (p[i].Width < 0 || p[i].Height < 0) {
 187          _mesa_error(ctx, GL_INVALID_VALUE,
 188                      "glViewportArrayv: index (%d) width or height < 0 "
 189                      "(%f, %f)",
 190                      i + first, p[i].Width, p[i].Height);
 191          return;
 192       }
 193    }
 194
 195    for (i = 0; i < count; i++)
 196       set_viewport_no_notify(ctx, i + first,
 197                              p[i].X, p[i].Y,
 198                              p[i].Width, p[i].Height);
 199
 200    if (ctx->Driver.Viewport)
 201       ctx->Driver.Viewport(ctx);
 202 }
 203
 204 static void
 205 ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 206                  GLfloat w, GLfloat h, const char *function)
 207 {
 208    GET_CURRENT_CONTEXT(ctx);
 209
 210    if (MESA_VERBOSE & VERBOSE_API)
 211       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
 212                   function, index, x, y, w, h);
 213
 214    if (index >= ctx->Const.MaxViewports) {
 215       _mesa_error(ctx, GL_INVALID_VALUE,
 216                   "%s: index (%d) >= MaxViewports (%d)",
 217                   function, index, ctx->Const.MaxViewports);
 218       return;
 219    }
 220
 221    /* Verify width & height */
 222    if (w < 0 || h < 0) {
 223       _mesa_error(ctx, GL_INVALID_VALUE,
 224                   "%s: index (%d) width or height < 0 (%f, %f)",
 225                   function, index, w, h);
 226       return;
 227    }
 228
 229    _mesa_set_viewport(ctx, index, x, y, w, h);
 230 }
 231
 232 void GLAPIENTRY
 233 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 234                        GLfloat w, GLfloat h)
 235 {
 236    ViewportIndexedf(index, x, y, w, h, "glViewportIndexedf");
 237 }
 238
 239 void GLAPIENTRY
 240 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 241 {
 242    ViewportIndexedf(index, v[0], v[1], v[2], v[3], "glViewportIndexedfv");
 243 }
 244
 245 static void
 246 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 247                           GLclampd nearval, GLclampd farval)
 248 {
 249    double scale[3], translate[3];
 250
 251    if (ctx->ViewportArray[idx].Near == nearval &&
 252        ctx->ViewportArray[idx].Far == farval)
 253       return;
 254
 255    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 256    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 257    ctx->NewState |= _NEW_VIEWPORT;
 258
 259 #if 1
 260    /* XXX remove this someday.  Currently the DRI drivers rely on
 261     * the WindowMap matrix being up to date in the driver's Viewport
 262     * and DepthRange functions.
 263     */
 264    _mesa_get_viewport_xform(ctx, idx, scale, translate);
 265    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
 266                          scale, translate, ctx->DrawBuffer->_DepthMaxF);
 267 #endif
 268 }
 269
 270 void
 271 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 272                       GLclampd nearval, GLclampd farval)
 273 {
 274    set_depth_range_no_notify(ctx, idx, nearval, farval);
 275
 276    if (ctx->Driver.DepthRange)
 277       ctx->Driver.DepthRange(ctx);
 278 }
 279
 280 /**
 281  * Called by glDepthRange
 282  *
 283  * \param nearval  specifies the Z buffer value which should correspond to
 284  *                 the near clip plane
 285  * \param farval  specifies the Z buffer value which should correspond to
 286  *                the far clip plane
 287  */
 288 void GLAPIENTRY
 289 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 290 {
 291    unsigned i;
 292    GET_CURRENT_CONTEXT(ctx);
 293
 294    FLUSH_VERTICES(ctx, 0);
 295
 296    if (MESA_VERBOSE&VERBOSE_API)
 297       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 298
 299    /* The GL_ARB_viewport_array spec says:
 300     *
 301     *     "DepthRange sets the depth range for all viewports to the same
 302     *     values and is equivalent (assuming no errors are generated) to:
 303     *
 304     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 305     *         DepthRangeIndexed(i, n, f);"
 306     *
 307     * Set the depth range for all of the viewports supported by the
 308     * implementation, but only signal the driver once at the end.
 309     */
 310    for (i = 0; i < ctx->Const.MaxViewports; i++)
 311       set_depth_range_no_notify(ctx, i, nearval, farval);
 312
 313    if (ctx->Driver.DepthRange) {
 314       ctx->Driver.DepthRange(ctx);
 315    }
 316 }
 317
 318 void GLAPIENTRY
 319 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 320 {
 321    _mesa_DepthRange(nearval, farval);
 322 }
 323
 324 /**
 325  * Update a range DepthRange values
 326  *
 327  * \param first   starting array index
 328  * \param count   count of DepthRange items to update
 329  * \param v       pointer to memory containing
 330  *                GLclampd near and far clip-plane values
 331  */
 332 void GLAPIENTRY
 333 _mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
 334 {
 335    int i;
 336    const struct gl_depthrange_inputs *const p =
 337       (struct gl_depthrange_inputs *) v;
 338    GET_CURRENT_CONTEXT(ctx);
 339
 340    if (MESA_VERBOSE & VERBOSE_API)
 341       _mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);
 342
 343    if ((first + count) > ctx->Const.MaxViewports) {
 344       _mesa_error(ctx, GL_INVALID_VALUE,
 345                   "glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
 346                   first, count, ctx->Const.MaxViewports);
 347       return;
 348    }
 349
 350    for (i = 0; i < count; i++)
 351       set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);
 352
 353    if (ctx->Driver.DepthRange)
 354       ctx->Driver.DepthRange(ctx);
 355 }
 356
 357 /**
 358  * Update a single DepthRange
 359  *
 360  * \param index    array index to update
 361  * \param nearval  specifies the Z buffer value which should correspond to
 362  *                 the near clip plane
 363  * \param farval   specifies the Z buffer value which should correspond to
 364  *                 the far clip plane
 365  */
 366 void GLAPIENTRY
 367 _mesa_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
 368 {
 369    GET_CURRENT_CONTEXT(ctx);
 370
 371    if (MESA_VERBOSE & VERBOSE_API)
 372       _mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
 373                   index, nearval, farval);
 374
 375    if (index >= ctx->Const.MaxViewports) {
 376       _mesa_error(ctx, GL_INVALID_VALUE,
 377                   "glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
 378                   index, ctx->Const.MaxViewports);
 379       return;
 380    }
 381
 382    _mesa_set_depth_range(ctx, index, nearval, farval);
 383 }
 384
 385 /**
 386  * Initialize the context viewport attribute group.
 387  * \param ctx  the GL context.
 388  */
 389 void _mesa_init_viewport(struct gl_context *ctx)
 390 {
 391    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 392    unsigned i;
 393
 394    ctx->Transform.ClipOrigin = GL_LOWER_LEFT;
 395    ctx->Transform.ClipDepthMode = GL_NEGATIVE_ONE_TO_ONE;
 396
 397    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 398     * so just initialize all of them.
 399     */
 400    for (i = 0; i < MAX_VIEWPORTS; i++) {
 401       double scale[3], translate[3];
 402
 403       /* Viewport group */
 404       ctx->ViewportArray[i].X = 0;
 405       ctx->ViewportArray[i].Y = 0;
 406       ctx->ViewportArray[i].Width = 0;
 407       ctx->ViewportArray[i].Height = 0;
 408       ctx->ViewportArray[i].Near = 0.0;
 409       ctx->ViewportArray[i].Far = 1.0;
 410       _math_matrix_ctr(&ctx->ViewportArray[i]._WindowMap);
 411
 412       _mesa_get_viewport_xform(ctx, i, scale, translate);
 413       _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap,
 414                             scale, translate, depthMax);
 415    }
 416 }
 417
 418
 419 /**
 420  * Free the context viewport attribute group data.
 421  * \param ctx  the GL context.
 422  */
 423 void _mesa_free_viewport_data(struct gl_context *ctx)
 424 {
 425    unsigned i;
 426
 427    for (i = 0; i < MAX_VIEWPORTS; i++)
 428       _math_matrix_dtr(&ctx->ViewportArray[i]._WindowMap);
 429 }
 430
 431 extern void GLAPIENTRY
 432 _mesa_ClipControl(GLenum origin, GLenum depth)
 433 {
 434    GET_CURRENT_CONTEXT(ctx);
 435
 436    if (MESA_VERBOSE&VERBOSE_API)
 437       _mesa_debug(ctx, "glClipControl(%s, %s)\n",
 438                   _mesa_lookup_enum_by_nr(origin),
 439                   _mesa_lookup_enum_by_nr(depth));
 440
 441    ASSERT_OUTSIDE_BEGIN_END(ctx);
 442
 443    if (!ctx->Extensions.ARB_clip_control) {
 444       _mesa_error(ctx, GL_INVALID_OPERATION, "glClipControl");
 445       return;
 446    }
 447
 448    if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
 449       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 450       return;
 451    }
 452
 453    if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
 454       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
 455       return;
 456    }
 457
 458    if (ctx->Transform.ClipOrigin == origin &&
 459        ctx->Transform.ClipDepthMode == depth)
 460       return;
 461
 462    /* Affects transform state and the viewport transform */
 463    FLUSH_VERTICES(ctx, _NEW_TRANSFORM | _NEW_VIEWPORT);
 464
 465    if (ctx->Transform.ClipOrigin != origin) {
 466       ctx->Transform.ClipOrigin = origin;
 467
 468       /* Affects the winding order of the front face. */
 469       ctx->NewState |= _NEW_POLYGON;
 470
 471       if (ctx->Driver.FrontFace)
 472          ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
 473    }
 474
 475    if (ctx->Transform.ClipDepthMode != depth) {
 476       ctx->Transform.ClipDepthMode = depth;
 477
 478       if (ctx->Driver.DepthRange)
 479          ctx->Driver.DepthRange(ctx);
 480    }
 481 }
 482
 483 /**
 484  * Computes the scaling and the translation part of the
 485  * viewport transform matrix of the \param i-th viewport
 486  * and writes that into \param scale and \param translate.
 487  */
 488 void
 489 _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
 490                          double scale[3], double translate[3])
 491 {
 492    double x = ctx->ViewportArray[i].X;
 493    double y = ctx->ViewportArray[i].Y;
 494    double half_width = 0.5*ctx->ViewportArray[i].Width;
 495    double half_height = 0.5*ctx->ViewportArray[i].Height;
 496    double n = ctx->ViewportArray[i].Near;
 497    double f = ctx->ViewportArray[i].Far;
 498
 499    scale[0] = half_width;
 500    translate[0] = half_width + x;
 501    if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
 502       scale[1] = -half_height;
 503       translate[1] = half_height - y;
 504    } else {
 505       scale[1] = half_height;
 506       translate[1] = half_height + y;
 507    }
 508    if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
 509       scale[2] = 0.5*(f - n);
 510       translate[2] = 0.5*(n + f);
 511    } else {
 512       scale[2] = f - n;
 513       translate[2] = n;
 514    }
 515 }