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    GET_CURRENT_CONTEXT(ctx);
  78    FLUSH_VERTICES(ctx, 0);
  79
  80    if (MESA_VERBOSE & VERBOSE_API)
  81       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
  82
  83    if (width < 0 || height < 0) {
  84       _mesa_error(ctx,  GL_INVALID_VALUE,
  85                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
  86       return;
  87    }
  88
  89    set_viewport_no_notify(ctx, 0, x, y, width, height);
  90
  91    if (ctx->Driver.Viewport) {
  92       /* Many drivers will use this call to check for window size changes
  93        * and reallocate the z/stencil/accum/etc buffers if needed.
  94        */
  95       ctx->Driver.Viewport(ctx);
  96    }
  97 }
  98
  99
 100 /**
 101  * Set new viewport parameters and update derived state (the _WindowMap
 102  * matrix).  Usually called from _mesa_Viewport().
 103  *
 104  * \param ctx GL context.
 105  * \param idx    Index of the viewport to be updated.
 106  * \param x, y coordinates of the lower left corner of the viewport rectangle.
 107  * \param width width of the viewport rectangle.
 108  * \param height height of the viewport rectangle.
 109  */
 110 void
 111 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLint x, GLint y,
 112                     GLsizei width, GLsizei height)
 113 {
 114    set_viewport_no_notify(ctx, idx, x, y, width, height);
 115
 116    if (ctx->Driver.Viewport) {
 117       /* Many drivers will use this call to check for window size changes
 118        * and reallocate the z/stencil/accum/etc buffers if needed.
 119        */
 120       ctx->Driver.Viewport(ctx);
 121    }
 122 }
 123
 124 static void
 125 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 126                           GLclampd nearval, GLclampd farval)
 127 {
 128    if (ctx->ViewportArray[idx].Near == nearval &&
 129        ctx->ViewportArray[idx].Far == farval)
 130       return;
 131
 132    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 133    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 134    ctx->NewState |= _NEW_VIEWPORT;
 135
 136 #if 1
 137    /* XXX remove this someday.  Currently the DRI drivers rely on
 138     * the WindowMap matrix being up to date in the driver's Viewport
 139     * and DepthRange functions.
 140     */
 141    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
 142                          ctx->ViewportArray[idx].X,
 143                          ctx->ViewportArray[idx].Y,
 144                          ctx->ViewportArray[idx].Width,
 145                          ctx->ViewportArray[idx].Height,
 146                          ctx->ViewportArray[idx].Near,
 147                          ctx->ViewportArray[idx].Far,
 148                          ctx->DrawBuffer->_DepthMaxF);
 149 #endif
 150 }
 151
 152 void
 153 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 154                       GLclampd nearval, GLclampd farval)
 155 {
 156    set_depth_range_no_notify(ctx, idx, nearval, farval);
 157
 158    if (ctx->Driver.DepthRange)
 159       ctx->Driver.DepthRange(ctx);
 160 }
 161
 162 /**
 163  * Called by glDepthRange
 164  *
 165  * \param nearval  specifies the Z buffer value which should correspond to
 166  *                 the near clip plane
 167  * \param farval  specifies the Z buffer value which should correspond to
 168  *                the far clip plane
 169  */
 170 void GLAPIENTRY
 171 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 172 {
 173    GET_CURRENT_CONTEXT(ctx);
 174
 175    FLUSH_VERTICES(ctx, 0);
 176
 177    if (MESA_VERBOSE&VERBOSE_API)
 178       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 179
 180    set_depth_range_no_notify(ctx, 0, nearval, farval);
 181
 182    if (ctx->Driver.DepthRange) {
 183       ctx->Driver.DepthRange(ctx);
 184    }
 185 }
 186
 187 void GLAPIENTRY
 188 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 189 {
 190    _mesa_DepthRange(nearval, farval);
 191 }
 192
 193 /**
 194  * Initialize the context viewport attribute group.
 195  * \param ctx  the GL context.
 196  */
 197 void _mesa_init_viewport(struct gl_context *ctx)
 198 {
 199    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 200    unsigned i;
 201
 202    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
 203     * so just initialize all of them.
 204     */
 205    for (i = 0; i < MAX_VIEWPORTS; i++) {
 206       /* Viewport group */
 207       ctx->ViewportArray[i].X = 0;
 208       ctx->ViewportArray[i].Y = 0;
 209       ctx->ViewportArray[i].Width = 0;
 210       ctx->ViewportArray[i].Height = 0;
 211       ctx->ViewportArray[i].Near = 0.0;
 212       ctx->ViewportArray[i].Far = 1.0;
 213       _math_matrix_ctr(&ctx->ViewportArray[i]._WindowMap);
 214
 215       _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap, 0, 0, 0, 0,
 216                             0.0F, 1.0F, depthMax);
 217    }
 218 }
 219
 220
 221 /**
 222  * Free the context viewport attribute group data.
 223  * \param ctx  the GL context.
 224  */
 225 void _mesa_free_viewport_data(struct gl_context *ctx)
 226 {
 227    unsigned i;
 228
 229    for (i = 0; i < MAX_VIEWPORTS; i++)
 230       _math_matrix_dtr(&ctx->ViewportArray[i]._WindowMap);
 231 }
 232