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, GLint x, GLint y,
  39                        GLsizei width, GLsizei height)
  40 {
  41    /* clamp width and height to the implementation dependent range */
  42    width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
  43    height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
  44
  45    ctx->ViewportArray[idx].X = x;
  46    ctx->ViewportArray[idx].Width = width;
  47    ctx->ViewportArray[idx].Y = y;
  48    ctx->ViewportArray[idx].Height = height;
  49    ctx->NewState |= _NEW_VIEWPORT;
  50
  51 #if 1
  52    /* XXX remove this someday.  Currently the DRI drivers rely on
  53     * the WindowMap matrix being up to date in the driver's Viewport
  54     * and DepthRange functions.
  55     */
  56    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
  57                          ctx->ViewportArray[idx].X,
  58                          ctx->ViewportArray[idx].Y,
  59                          ctx->ViewportArray[idx].Width,
  60                          ctx->ViewportArray[idx].Height,
  61                          ctx->ViewportArray[idx].Near,
  62                          ctx->ViewportArray[idx].Far,
  63                          ctx->DrawBuffer->_DepthMaxF);
  64 #endif
  65 }
  66
  67 /**
  68  * Set the viewport.
  69  * \sa Called via glViewport() or display list execution.
  70  *
  71  * Flushes the vertices and calls _mesa_set_viewport() with the given
  72  * parameters.
  73  */
  74 void GLAPIENTRY
  75 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
  76 {
  77    unsigned i;
  78    GET_CURRENT_CONTEXT(ctx);
  79    FLUSH_VERTICES(ctx, 0);
  80
  81    if (MESA_VERBOSE & VERBOSE_API)
  82       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
  83
  84    if (width < 0 || height < 0) {
  85       _mesa_error(ctx,  GL_INVALID_VALUE,
  86                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
  87       return;
  88    }
  89
  90    /* The GL_ARB_viewport_array spec says:
  91     *
  92     *     "Viewport sets the parameters for all viewports to the same values
  93     *     and is equivalent (assuming no errors are generated) to:
  94     *
  95     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
  96     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
  97     *
  98     * Set all of the viewports supported by the implementation, but only
  99     * signal the driver once at the end.
 100     */
 101    for (i = 0; i < ctx->Const.MaxViewports; i++)
 102       set_viewport_no_notify(ctx, i, x, y, width, height);
 103
 104    if (ctx->Driver.Viewport) {
 105       /* Many drivers will use this call to check for window size changes
 106        * and reallocate the z/stencil/accum/etc buffers if needed.
 107        */
 108       ctx->Driver.Viewport(ctx);
 109    }
 110 }
 111
 112
 113 /**
 114  * Set new viewport parameters and update derived state (the _WindowMap
 115  * matrix).  Usually called from _mesa_Viewport().
 116  *
 117  * \param ctx GL context.
 118  * \param idx    Index of the viewport to be updated.
 119  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 120  * \param width width of the viewport rectangle.
 121  * \param height height of the viewport rectangle.
 122  */
 123 void
 124 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLint x, GLint y,
 125                     GLsizei width, GLsizei height)
 126 {
 127    set_viewport_no_notify(ctx, idx, 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 static void
 138 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 139                           GLclampd nearval, GLclampd farval)
 140 {
 141    if (ctx->ViewportArray[idx].Near == nearval &&
 142        ctx->ViewportArray[idx].Far == farval)
 143       return;
 144
 145    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 146    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 147    ctx->NewState |= _NEW_VIEWPORT;
 148
 149 #if 1
 150    /* XXX remove this someday.  Currently the DRI drivers rely on
 151     * the WindowMap matrix being up to date in the driver's Viewport
 152     * and DepthRange functions.
 153     */
 154    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
 155                          ctx->ViewportArray[idx].X,
 156                          ctx->ViewportArray[idx].Y,
 157                          ctx->ViewportArray[idx].Width,
 158                          ctx->ViewportArray[idx].Height,
 159                          ctx->ViewportArray[idx].Near,
 160                          ctx->ViewportArray[idx].Far,
 161                          ctx->DrawBuffer->_DepthMaxF);
 162 #endif
 163 }
 164
 165 void
 166 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 167                       GLclampd nearval, GLclampd farval)
 168 {
 169    set_depth_range_no_notify(ctx, idx, nearval, farval);
 170
 171    if (ctx->Driver.DepthRange)
 172       ctx->Driver.DepthRange(ctx);
 173 }
 174
 175 /**
 176  * Called by glDepthRange
 177  *
 178  * \param nearval  specifies the Z buffer value which should correspond to
 179  *                 the near clip plane
 180  * \param farval  specifies the Z buffer value which should correspond to
 181  *                the far clip plane
 182  */
 183 void GLAPIENTRY
 184 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 185 {
 186    unsigned i;
 187    GET_CURRENT_CONTEXT(ctx);
 188
 189    FLUSH_VERTICES(ctx, 0);
 190
 191    if (MESA_VERBOSE&VERBOSE_API)
 192       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 193
 194    /* The GL_ARB_viewport_array spec says:
 195     *
 196     *     "DepthRange sets the depth range for all viewports to the same
 197     *     values and is equivalent (assuming no errors are generated) to:
 198     *
 199     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
 200     *         DepthRangeIndexed(i, n, f);"
 201     *
 202     * Set the depth range for all of the viewports supported by the
 203     * implementation, but only signal the driver once at the end.
 204     */
 205    for (i = 0; i < ctx->Const.MaxViewports; i++)
 206       set_depth_range_no_notify(ctx, i, nearval, farval);
 207
 208    if (ctx->Driver.DepthRange) {
 209       ctx->Driver.DepthRange(ctx);
 210    }
 211 }
 212
 213 void GLAPIENTRY
 214 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 215 {
 216    _mesa_DepthRange(nearval, farval);
 217 }
 218
 219 /**
 220  * Initialize the context viewport attribute group.
 221  * \param ctx  the GL context.
 222  */
 223 void _mesa_init_viewport(struct gl_context *ctx)
 224 {
 225    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 226    unsigned i;
 227
 228    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 229     * so just initialize all of them.
 230     */
 231    for (i = 0; i < MAX_VIEWPORTS; i++) {
 232       /* Viewport group */
 233       ctx->ViewportArray[i].X = 0;
 234       ctx->ViewportArray[i].Y = 0;
 235       ctx->ViewportArray[i].Width = 0;
 236       ctx->ViewportArray[i].Height = 0;
 237       ctx->ViewportArray[i].Near = 0.0;
 238       ctx->ViewportArray[i].Far = 1.0;
 239       _math_matrix_ctr(&ctx->ViewportArray[i]._WindowMap);
 240
 241       _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap, 0, 0, 0, 0,
 242                             0.0F, 1.0F, depthMax);
 243    }
 244 }
 245
 246
 247 /**
 248  * Free the context viewport attribute group data.
 249  * \param ctx  the GL context.
 250  */
 251 void _mesa_free_viewport_data(struct gl_context *ctx)
 252 {
 253    unsigned i;
 254
 255    for (i = 0; i < MAX_VIEWPORTS; i++)
 256       _math_matrix_dtr(&ctx->ViewportArray[i]._WindowMap);
 257 }
 258