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