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 "macros.h"
  34 #include "mtypes.h"
  35 #include "viewport.h"
  36
  37 static void
  38 set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
  39                        GLfloat x, GLfloat y,
  40                        GLfloat width, GLfloat height)
  41 {
  42    double scale[3], translate[3];
  43
  44    /* clamp width and height to the implementation dependent range */
  45    width  = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
  46    height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);
  47
  48    /* The GL_ARB_viewport_array spec says:
  49     *
  50     *     "The location of the viewport's bottom-left corner, given by (x,y),
  51     *     are clamped to be within the implementation-dependent viewport
  52     *     bounds range.  The viewport bounds range [min, max] tuple may be
  53     *     determined by calling GetFloatv with the symbolic constant
  54     *     VIEWPORT_BOUNDS_RANGE (see section 6.1)."
  55     */
  56    if (ctx->Extensions.ARB_viewport_array) {
  57       x = CLAMP(x,
  58                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  59       y = CLAMP(y,
  60                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  61    }
  62
  63    if (ctx->ViewportArray[idx].X == x &&
  64        ctx->ViewportArray[idx].Width == width &&
  65        ctx->ViewportArray[idx].Y == y &&
  66        ctx->ViewportArray[idx].Height == height)
  67       return;
  68
  69    ctx->ViewportArray[idx].X = x;
  70    ctx->ViewportArray[idx].Width = width;
  71    ctx->ViewportArray[idx].Y = y;
  72    ctx->ViewportArray[idx].Height = height;
  73    ctx->NewState |= _NEW_VIEWPORT;
  74
  75 #if 1
  76    /* XXX remove this someday.  Currently the DRI drivers rely on
  77     * the WindowMap matrix being up to date in the driver's Viewport
  78     * and DepthRange functions.
  79     */
  80    _mesa_get_viewport_xform(ctx, idx, scale, translate);
  81    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
  82                          scale, translate, ctx->DrawBuffer->_DepthMaxF);
  83 #endif
  84 }
  85
  86 struct gl_viewport_inputs {
  87    GLfloat X, Y;                /**< position */
  88    GLfloat Width, Height;       /**< size */
  89 };
  90
  91 struct gl_depthrange_inputs {
  92    GLdouble Near, Far;          /**< Depth buffer range */
  93 };
  94
  95 /**
  96  * Set the viewport.
  97  * \sa Called via glViewport() or display list execution.
  98  *
  99  * Flushes the vertices and calls _mesa_set_viewport() with the given
 100  * parameters.
 101  */
 102 void GLAPIENTRY
 103 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
 104 {
 105    unsigned i;
 106    GET_CURRENT_CONTEXT(ctx);
 107    FLUSH_VERTICES(ctx, 0);
 108
 109    if (MESA_VERBOSE & VERBOSE_API)
 110       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
 111
 112    if (width < 0 || height < 0) {
 113       _mesa_error(ctx,  GL_INVALID_VALUE,
 114                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
 115       return;
 116    }
 117
 118    /* The GL_ARB_viewport_array spec says:
 119     *
 120     *     "Viewport sets the parameters for all viewports to the same values
 121     *     and is equivalent (assuming no errors are generated) to:
 122     *
 123     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 124     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
 125     *
 126     * Set all of the viewports supported by the implementation, but only
 127     * signal the driver once at the end.
 128     */
 129    for (i = 0; i < ctx->Const.MaxViewports; i++)
 130       set_viewport_no_notify(ctx, i, x, y, width, height);
 131
 132    if (ctx->Driver.Viewport) {
 133       /* Many drivers will use this call to check for window size changes
 134        * and reallocate the z/stencil/accum/etc buffers if needed.
 135        */
 136       ctx->Driver.Viewport(ctx);
 137    }
 138 }
 139
 140
 141 /**
 142  * Set new viewport parameters and update derived state (the _WindowMap
 143  * matrix).  Usually called from _mesa_Viewport().
 144  *
 145  * \param ctx GL context.
 146  * \param idx    Index of the viewport to be updated.
 147  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 148  * \param width width of the viewport rectangle.
 149  * \param height height of the viewport rectangle.
 150  */
 151 void
 152 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLfloat x, GLfloat y,
 153                     GLfloat width, GLfloat height)
 154 {
 155    set_viewport_no_notify(ctx, idx, x, y, width, height);
 156
 157    if (ctx->Driver.Viewport) {
 158       /* Many drivers will use this call to check for window size changes
 159        * and reallocate the z/stencil/accum/etc buffers if needed.
 160        */
 161       ctx->Driver.Viewport(ctx);
 162    }
 163 }
 164
 165 void GLAPIENTRY
 166 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 167 {
 168    int i;
 169    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *) v;
 170    GET_CURRENT_CONTEXT(ctx);
 171
 172    if (MESA_VERBOSE & VERBOSE_API)
 173       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);
 174
 175    if ((first + count) > ctx->Const.MaxViewports) {
 176       _mesa_error(ctx, GL_INVALID_VALUE,
 177                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
 178                   "(%d)",
 179                   first, count, ctx->Const.MaxViewports);
 180       return;
 181    }
 182
 183    /* Verify width & height */
 184    for (i = 0; i < count; i++) {
 185       if (p[i].Width < 0 || p[i].Height < 0) {
 186          _mesa_error(ctx, GL_INVALID_VALUE,
 187                      "glViewportArrayv: index (%d) width or height < 0 "
 188                      "(%f, %f)",
 189                      i + first, p[i].Width, p[i].Height);
 190          return;
 191       }
 192    }
 193
 194    for (i = 0; i < count; i++)
 195       set_viewport_no_notify(ctx, i + first,
 196                              p[i].X, p[i].Y,
 197                              p[i].Width, p[i].Height);
 198
 199    if (ctx->Driver.Viewport)
 200       ctx->Driver.Viewport(ctx);
 201 }
 202
 203 static void
 204 ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 205                  GLfloat w, GLfloat h, const char *function)
 206 {
 207    GET_CURRENT_CONTEXT(ctx);
 208
 209    if (MESA_VERBOSE & VERBOSE_API)
 210       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
 211                   function, index, x, y, w, h);
 212
 213    if (index >= ctx->Const.MaxViewports) {
 214       _mesa_error(ctx, GL_INVALID_VALUE,
 215                   "%s: index (%d) >= MaxViewports (%d)",
 216                   function, index, ctx->Const.MaxViewports);
 217       return;
 218    }
 219
 220    /* Verify width & height */
 221    if (w < 0 || h < 0) {
 222       _mesa_error(ctx, GL_INVALID_VALUE,
 223                   "%s: index (%d) width or height < 0 (%f, %f)",
 224                   function, index, w, h);
 225       return;
 226    }
 227
 228    _mesa_set_viewport(ctx, index, x, y, w, h);
 229 }
 230
 231 void GLAPIENTRY
 232 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 233                        GLfloat w, GLfloat h)
 234 {
 235    ViewportIndexedf(index, x, y, w, h, "glViewportIndexedf");
 236 }
 237
 238 void GLAPIENTRY
 239 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 240 {
 241    ViewportIndexedf(index, v[0], v[1], v[2], v[3], "glViewportIndexedfv");
 242 }
 243
 244 static void
 245 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 246                           GLclampd nearval, GLclampd farval)
 247 {
 248    double scale[3], translate[3];
 249
 250    if (ctx->ViewportArray[idx].Near == nearval &&
 251        ctx->ViewportArray[idx].Far == farval)
 252       return;
 253
 254    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 255    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 256    ctx->NewState |= _NEW_VIEWPORT;
 257
 258 #if 1
 259    /* XXX remove this someday.  Currently the DRI drivers rely on
 260     * the WindowMap matrix being up to date in the driver's Viewport
 261     * and DepthRange functions.
 262     */
 263    _mesa_get_viewport_xform(ctx, idx, scale, translate);
 264    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
 265                          scale, translate, ctx->DrawBuffer->_DepthMaxF);
 266 #endif
 267 }
 268
 269 void
 270 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 271                       GLclampd nearval, GLclampd farval)
 272 {
 273    set_depth_range_no_notify(ctx, idx, nearval, farval);
 274
 275    if (ctx->Driver.DepthRange)
 276       ctx->Driver.DepthRange(ctx);
 277 }
 278
 279 /**
 280  * Called by glDepthRange
 281  *
 282  * \param nearval  specifies the Z buffer value which should correspond to
 283  *                 the near clip plane
 284  * \param farval  specifies the Z buffer value which should correspond to
 285  *                the far clip plane
 286  */
 287 void GLAPIENTRY
 288 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 289 {
 290    unsigned i;
 291    GET_CURRENT_CONTEXT(ctx);
 292
 293    FLUSH_VERTICES(ctx, 0);
 294
 295    if (MESA_VERBOSE&VERBOSE_API)
 296       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 297
 298    /* The GL_ARB_viewport_array spec says:
 299     *
 300     *     "DepthRange sets the depth range for all viewports to the same
 301     *     values and is equivalent (assuming no errors are generated) to:
 302     *
 303     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 304     *         DepthRangeIndexed(i, n, f);"
 305     *
 306     * Set the depth range for all of the viewports supported by the
 307     * implementation, but only signal the driver once at the end.
 308     */
 309    for (i = 0; i < ctx->Const.MaxViewports; i++)
 310       set_depth_range_no_notify(ctx, i, nearval, farval);
 311
 312    if (ctx->Driver.DepthRange) {
 313       ctx->Driver.DepthRange(ctx);
 314    }
 315 }
 316
 317 void GLAPIENTRY
 318 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 319 {
 320    _mesa_DepthRange(nearval, farval);
 321 }
 322
 323 /**
 324  * Update a range DepthRange values
 325  *
 326  * \param first   starting array index
 327  * \param count   count of DepthRange items to update
 328  * \param v       pointer to memory containing
 329  *                GLclampd near and far clip-plane values
 330  */
 331 void GLAPIENTRY
 332 _mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
 333 {
 334    int i;
 335    const struct gl_depthrange_inputs *const p =
 336       (struct gl_depthrange_inputs *) v;
 337    GET_CURRENT_CONTEXT(ctx);
 338
 339    if (MESA_VERBOSE & VERBOSE_API)
 340       _mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);
 341
 342    if ((first + count) > ctx->Const.MaxViewports) {
 343       _mesa_error(ctx, GL_INVALID_VALUE,
 344                   "glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
 345                   first, count, ctx->Const.MaxViewports);
 346       return;
 347    }
 348
 349    for (i = 0; i < count; i++)
 350       set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);
 351
 352    if (ctx->Driver.DepthRange)
 353       ctx->Driver.DepthRange(ctx);
 354 }
 355
 356 /**
 357  * Update a single DepthRange
 358  *
 359  * \param index    array index to update
 360  * \param nearval  specifies the Z buffer value which should correspond to
 361  *                 the near clip plane
 362  * \param farval   specifies the Z buffer value which should correspond to
 363  *                 the far clip plane
 364  */
 365 void GLAPIENTRY
 366 _mesa_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
 367 {
 368    GET_CURRENT_CONTEXT(ctx);
 369
 370    if (MESA_VERBOSE & VERBOSE_API)
 371       _mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
 372                   index, nearval, farval);
 373
 374    if (index >= ctx->Const.MaxViewports) {
 375       _mesa_error(ctx, GL_INVALID_VALUE,
 376                   "glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
 377                   index, ctx->Const.MaxViewports);
 378       return;
 379    }
 380
 381    _mesa_set_depth_range(ctx, index, nearval, farval);
 382 }
 383
 384 /**
 385  * Initialize the context viewport attribute group.
 386  * \param ctx  the GL context.
 387  */
 388 void _mesa_init_viewport(struct gl_context *ctx)
 389 {
 390    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 391    unsigned i;
 392
 393    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 394     * so just initialize all of them.
 395     */
 396    for (i = 0; i < MAX_VIEWPORTS; i++) {
 397       double scale[3], translate[3];
 398
 399       /* Viewport group */
 400       ctx->ViewportArray[i].X = 0;
 401       ctx->ViewportArray[i].Y = 0;
 402       ctx->ViewportArray[i].Width = 0;
 403       ctx->ViewportArray[i].Height = 0;
 404       ctx->ViewportArray[i].Near = 0.0;
 405       ctx->ViewportArray[i].Far = 1.0;
 406       _math_matrix_ctr(&ctx->ViewportArray[i]._WindowMap);
 407
 408       _mesa_get_viewport_xform(ctx, i, scale, translate);
 409       _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap,
 410                             scale, translate, depthMax);
 411    }
 412 }
 413
 414
 415 /**
 416  * Free the context viewport attribute group data.
 417  * \param ctx  the GL context.
 418  */
 419 void _mesa_free_viewport_data(struct gl_context *ctx)
 420 {
 421    unsigned i;
 422
 423    for (i = 0; i < MAX_VIEWPORTS; i++)
 424       _math_matrix_dtr(&ctx->ViewportArray[i]._WindowMap);
 425 }
 426
 427 /**
 428  * Computes the scaling and the translation part of the
 429  * viewport transform matrix of the \param i-th viewport
 430  * and writes that into \param scale and \param translate.
 431  */
 432 void
 433 _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
 434                          double scale[3], double translate[3])
 435 {
 436    double x = ctx->ViewportArray[i].X;
 437    double y = ctx->ViewportArray[i].Y;
 438    double half_width = 0.5*ctx->ViewportArray[i].Width;
 439    double half_height = 0.5*ctx->ViewportArray[i].Height;
 440    double n = ctx->ViewportArray[i].Near;
 441    double f = ctx->ViewportArray[i].Far;
 442
 443    scale[0] = half_width;
 444    translate[0] = half_width + x;
 445    scale[1] = half_height;
 446    translate[1] = half_height + y;
 447    scale[2] = 0.5*(f - n);
 448    translate[2] = 0.5*(n + f);
 449 }