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    /* clamp width and height to the implementation dependent range */
  43    width  = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
  44    height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);
  45
  46    /* The GL_ARB_viewport_array spec says:
  47     *
  48     *     "The location of the viewport's bottom-left corner, given by (x,y),
  49     *     are clamped to be within the implementation-dependent viewport
  50     *     bounds range.  The viewport bounds range [min, max] tuple may be
  51     *     determined by calling GetFloatv with the symbolic constant
  52     *     VIEWPORT_BOUNDS_RANGE (see section 6.1)."
  53     */
  54    if (ctx->Extensions.ARB_viewport_array) {
  55       x = CLAMP(x,
  56                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  57       y = CLAMP(y,
  58                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
  59    }
  60
  61    ctx->ViewportArray[idx].X = x;
  62    ctx->ViewportArray[idx].Width = width;
  63    ctx->ViewportArray[idx].Y = y;
  64    ctx->ViewportArray[idx].Height = height;
  65    ctx->NewState |= _NEW_VIEWPORT;
  66
  67 #if 1
  68    /* XXX remove this someday.  Currently the DRI drivers rely on
  69     * the WindowMap matrix being up to date in the driver's Viewport
  70     * and DepthRange functions.
  71     */
  72    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
  73                          ctx->ViewportArray[idx].X,
  74                          ctx->ViewportArray[idx].Y,
  75                          ctx->ViewportArray[idx].Width,
  76                          ctx->ViewportArray[idx].Height,
  77                          ctx->ViewportArray[idx].Near,
  78                          ctx->ViewportArray[idx].Far,
  79                          ctx->DrawBuffer->_DepthMaxF);
  80 #endif
  81 }
  82
  83 struct gl_viewport_inputs {
  84    GLfloat X, Y;                /**< position */
  85    GLfloat Width, Height;       /**< size */
  86 };
  87
  88 struct gl_depthrange_inputs {
  89    GLdouble Near, Far;          /**< Depth buffer range */
  90 };
  91
  92 /**
  93  * Set the viewport.
  94  * \sa Called via glViewport() or display list execution.
  95  *
  96  * Flushes the vertices and calls _mesa_set_viewport() with the given
  97  * parameters.
  98  */
  99 void GLAPIENTRY
 100 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
 101 {
 102    unsigned i;
 103    GET_CURRENT_CONTEXT(ctx);
 104    FLUSH_VERTICES(ctx, 0);
 105
 106    if (MESA_VERBOSE & VERBOSE_API)
 107       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
 108
 109    if (width < 0 || height < 0) {
 110       _mesa_error(ctx,  GL_INVALID_VALUE,
 111                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
 112       return;
 113    }
 114
 115    /* The GL_ARB_viewport_array spec says:
 116     *
 117     *     "Viewport sets the parameters for all viewports to the same values
 118     *     and is equivalent (assuming no errors are generated) to:
 119     *
 120     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 121     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
 122     *
 123     * Set all of the viewports supported by the implementation, but only
 124     * signal the driver once at the end.
 125     */
 126    for (i = 0; i < ctx->Const.MaxViewports; i++)
 127       set_viewport_no_notify(ctx, i, x, y, width, height);
 128
 129    if (ctx->Driver.Viewport) {
 130       /* Many drivers will use this call to check for window size changes
 131        * and reallocate the z/stencil/accum/etc buffers if needed.
 132        */
 133       ctx->Driver.Viewport(ctx);
 134    }
 135 }
 136
 137
 138 /**
 139  * Set new viewport parameters and update derived state (the _WindowMap
 140  * matrix).  Usually called from _mesa_Viewport().
 141  *
 142  * \param ctx GL context.
 143  * \param idx    Index of the viewport to be updated.
 144  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 145  * \param width width of the viewport rectangle.
 146  * \param height height of the viewport rectangle.
 147  */
 148 void
 149 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLfloat x, GLfloat y,
 150                     GLfloat width, GLfloat height)
 151 {
 152    set_viewport_no_notify(ctx, idx, x, y, width, height);
 153
 154    if (ctx->Driver.Viewport) {
 155       /* Many drivers will use this call to check for window size changes
 156        * and reallocate the z/stencil/accum/etc buffers if needed.
 157        */
 158       ctx->Driver.Viewport(ctx);
 159    }
 160 }
 161
 162 void GLAPIENTRY
 163 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 164 {
 165    int i;
 166    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *) v;
 167    GET_CURRENT_CONTEXT(ctx);
 168
 169    if (MESA_VERBOSE & VERBOSE_API)
 170       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);
 171
 172    if ((first + count) > ctx->Const.MaxViewports) {
 173       _mesa_error(ctx, GL_INVALID_VALUE,
 174                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
 175                   "(%d)",
 176                   first, count, ctx->Const.MaxViewports);
 177       return;
 178    }
 179
 180    /* Verify width & height */
 181    for (i = 0; i < count; i++) {
 182       if (p[i].Width < 0 || p[i].Height < 0) {
 183          _mesa_error(ctx, GL_INVALID_VALUE,
 184                      "glViewportArrayv: index (%d) width or height < 0 "
 185                      "(%f, %f)",
 186                      i + first, p[i].Width, p[i].Height);
 187          return;
 188       }
 189    }
 190
 191    for (i = 0; i < count; i++)
 192       set_viewport_no_notify(ctx, i + first,
 193                              p[i].X, p[i].Y,
 194                              p[i].Width, p[i].Height);
 195
 196    if (ctx->Driver.Viewport)
 197       ctx->Driver.Viewport(ctx);
 198 }
 199
 200 static void
 201 ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 202                  GLfloat w, GLfloat h, const char *function)
 203 {
 204    GET_CURRENT_CONTEXT(ctx);
 205
 206    if (MESA_VERBOSE & VERBOSE_API)
 207       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
 208                   function, index, x, y, w, h);
 209
 210    if (index >= ctx->Const.MaxViewports) {
 211       _mesa_error(ctx, GL_INVALID_VALUE,
 212                   "%s: index (%d) >= MaxViewports (%d)",
 213                   function, index, ctx->Const.MaxViewports);
 214       return;
 215    }
 216
 217    /* Verify width & height */
 218    if (w < 0 || h < 0) {
 219       _mesa_error(ctx, GL_INVALID_VALUE,
 220                   "%s: index (%d) width or height < 0 (%f, %f)",
 221                   function, index, w, h);
 222       return;
 223    }
 224
 225    _mesa_set_viewport(ctx, index, x, y, w, h);
 226 }
 227
 228 void GLAPIENTRY
 229 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
 230                        GLfloat w, GLfloat h)
 231 {
 232    ViewportIndexedf(index, x, y, w, h, "glViewportIndexedf");
 233 }
 234
 235 void GLAPIENTRY
 236 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 237 {
 238    ViewportIndexedf(index, v[0], v[1], v[2], v[3], "glViewportIndexedfv");
 239 }
 240
 241 static void
 242 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 243                           GLclampd nearval, GLclampd farval)
 244 {
 245    if (ctx->ViewportArray[idx].Near == nearval &&
 246        ctx->ViewportArray[idx].Far == farval)
 247       return;
 248
 249    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 250    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 251    ctx->NewState |= _NEW_VIEWPORT;
 252
 253 #if 1
 254    /* XXX remove this someday.  Currently the DRI drivers rely on
 255     * the WindowMap matrix being up to date in the driver's Viewport
 256     * and DepthRange functions.
 257     */
 258    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
 259                          ctx->ViewportArray[idx].X,
 260                          ctx->ViewportArray[idx].Y,
 261                          ctx->ViewportArray[idx].Width,
 262                          ctx->ViewportArray[idx].Height,
 263                          ctx->ViewportArray[idx].Near,
 264                          ctx->ViewportArray[idx].Far,
 265                          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       /* Viewport group */
 398       ctx->ViewportArray[i].X = 0;
 399       ctx->ViewportArray[i].Y = 0;
 400       ctx->ViewportArray[i].Width = 0;
 401       ctx->ViewportArray[i].Height = 0;
 402       ctx->ViewportArray[i].Near = 0.0;
 403       ctx->ViewportArray[i].Far = 1.0;
 404       _math_matrix_ctr(&ctx->ViewportArray[i]._WindowMap);
 405
 406       _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap, 0, 0, 0, 0,
 407                             0.0F, 1.0F, depthMax);
 408    }
 409 }
 410
 411
 412 /**
 413  * Free the context viewport attribute group data.
 414  * \param ctx  the GL context.
 415  */
 416 void _mesa_free_viewport_data(struct gl_context *ctx)
 417 {
 418    unsigned i;
 419
 420    for (i = 0; i < MAX_VIEWPORTS; i++)
 421       _math_matrix_dtr(&ctx->ViewportArray[i]._WindowMap);
 422 }
 423