src/mesa/main/viewport.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.5
   4  *
   5  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * \file viewport.c
  29  * glViewport and glDepthRange functions.
  30  */
  31
  32
  33 #include "context.h"
  34 #include "macros.h"
  35 #include "mtypes.h"
  36 #include "viewport.h"
  37
  38
  39 /**
  40  * Set the viewport.
  41  * \sa Called via glViewport() or display list execution.
  42  *
  43  * Flushes the vertices and calls _mesa_set_viewport() with the given
  44  * parameters.
  45  */
  46 void GLAPIENTRY
  47 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
  48 {
  49    GET_CURRENT_CONTEXT(ctx);
  50    FLUSH_VERTICES(ctx, 0);
  51    _mesa_set_viewport(ctx, x, y, width, height);
  52 }
  53
  54
  55 /**
  56  * Set new viewport parameters and update derived state (the _WindowMap
  57  * matrix).  Usually called from _mesa_Viewport().
  58  *
  59  * \param ctx GL context.
  60  * \param x, y coordinates of the lower left corner of the viewport rectangle.
  61  * \param width width of the viewport rectangle.
  62  * \param height height of the viewport rectangle.
  63  */
  64 void
  65 _mesa_set_viewport(struct gl_context *ctx, GLint x, GLint y,
  66                     GLsizei width, GLsizei height)
  67 {
  68    if (MESA_VERBOSE & VERBOSE_API)
  69       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
  70
  71    if (width < 0 || height < 0) {
  72       _mesa_error(ctx,  GL_INVALID_VALUE,
  73                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
  74       return;
  75    }
  76
  77    /* clamp width and height to the implementation dependent range */
  78    width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
  79    height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
  80
  81    ctx->Viewport.X = x;
  82    ctx->Viewport.Width = width;
  83    ctx->Viewport.Y = y;
  84    ctx->Viewport.Height = height;
  85    ctx->NewState |= _NEW_VIEWPORT;
  86
  87 #if 1
  88    /* XXX remove this someday.  Currently the DRI drivers rely on
  89     * the WindowMap matrix being up to date in the driver's Viewport
  90     * and DepthRange functions.
  91     */
  92    _math_matrix_viewport(&ctx->Viewport._WindowMap,
  93                          ctx->Viewport.X, ctx->Viewport.Y,
  94                          ctx->Viewport.Width, ctx->Viewport.Height,
  95                          ctx->Viewport.Near, ctx->Viewport.Far,
  96                          ctx->DrawBuffer->_DepthMaxF);
  97 #endif
  98
  99    if (ctx->Driver.Viewport) {
 100       /* Many drivers will use this call to check for window size changes
 101        * and reallocate the z/stencil/accum/etc buffers if needed.
 102        */
 103       ctx->Driver.Viewport(ctx, x, y, width, height);
 104    }
 105 }
 106
 107
 108 /**
 109  * Called by glDepthRange
 110  *
 111  * \param nearval  specifies the Z buffer value which should correspond to
 112  *                 the near clip plane
 113  * \param farval  specifies the Z buffer value which should correspond to
 114  *                the far clip plane
 115  */
 116 void GLAPIENTRY
 117 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 118 {
 119    GET_CURRENT_CONTEXT(ctx);
 120
 121    FLUSH_VERTICES(ctx, 0);
 122
 123    if (MESA_VERBOSE&VERBOSE_API)
 124       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 125
 126    if (ctx->Viewport.Near == nearval &&
 127        ctx->Viewport.Far == farval)
 128       return;
 129
 130    ctx->Viewport.Near = (GLfloat) CLAMP(nearval, 0.0, 1.0);
 131    ctx->Viewport.Far = (GLfloat) CLAMP(farval, 0.0, 1.0);
 132    ctx->NewState |= _NEW_VIEWPORT;
 133
 134 #if 1
 135    /* XXX remove this someday.  Currently the DRI drivers rely on
 136     * the WindowMap matrix being up to date in the driver's Viewport
 137     * and DepthRange functions.
 138     */
 139    _math_matrix_viewport(&ctx->Viewport._WindowMap,
 140                          ctx->Viewport.X, ctx->Viewport.Y,
 141                          ctx->Viewport.Width, ctx->Viewport.Height,
 142                          ctx->Viewport.Near, ctx->Viewport.Far,
 143                          ctx->DrawBuffer->_DepthMaxF);
 144 #endif
 145
 146    if (ctx->Driver.DepthRange) {
 147       ctx->Driver.DepthRange(ctx, nearval, farval);
 148    }
 149 }
 150
 151 void GLAPIENTRY
 152 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 153 {
 154    _mesa_DepthRange(nearval, farval);
 155 }
 156
 157 /**
 158  * Initialize the context viewport attribute group.
 159  * \param ctx  the GL context.
 160  */
 161 void _mesa_init_viewport(struct gl_context *ctx)
 162 {
 163    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 164
 165    /* Viewport group */
 166    ctx->Viewport.X = 0;
 167    ctx->Viewport.Y = 0;
 168    ctx->Viewport.Width = 0;
 169    ctx->Viewport.Height = 0;
 170    ctx->Viewport.Near = 0.0;
 171    ctx->Viewport.Far = 1.0;
 172    _math_matrix_ctr(&ctx->Viewport._WindowMap);
 173
 174    _math_matrix_viewport(&ctx->Viewport._WindowMap, 0, 0, 0, 0,
 175                          0.0F, 1.0F, depthMax);
 176 }
 177
 178
 179 /**
 180  * Free the context viewport attribute group data.
 181  * \param ctx  the GL context.
 182  */
 183 void _mesa_free_viewport_data(struct gl_context *ctx)
 184 {
 185    _math_matrix_dtr(&ctx->Viewport._WindowMap);
 186 }
 187