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 BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR 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
  38 /**
  39  * Set the viewport.
  40  * \sa Called via glViewport() or display list execution.
  41  *
  42  * Flushes the vertices and calls _mesa_set_viewport() with the given
  43  * parameters.
  44  */
  45 void GLAPIENTRY
  46 _mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
  47 {
  48    GET_CURRENT_CONTEXT(ctx);
  49    FLUSH_VERTICES(ctx, 0);
  50    _mesa_set_viewport(ctx, x, y, width, height);
  51 }
  52
  53
  54 /**
  55  * Set new viewport parameters and update derived state (the _WindowMap
  56  * matrix).  Usually called from _mesa_Viewport().
  57  *
  58  * \param ctx GL context.
  59  * \param x, y coordinates of the lower left corner of the viewport rectangle.
  60  * \param width width of the viewport rectangle.
  61  * \param height height of the viewport rectangle.
  62  */
  63 void
  64 _mesa_set_viewport(struct gl_context *ctx, GLint x, GLint y,
  65                     GLsizei width, GLsizei height)
  66 {
  67    if (MESA_VERBOSE & VERBOSE_API)
  68       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
  69
  70    if (width < 0 || height < 0) {
  71       _mesa_error(ctx,  GL_INVALID_VALUE,
  72                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
  73       return;
  74    }
  75
  76    /* clamp width and height to the implementation dependent range */
  77    width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
  78    height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
  79
  80    ctx->Viewport.X = x;
  81    ctx->Viewport.Width = width;
  82    ctx->Viewport.Y = y;
  83    ctx->Viewport.Height = height;
  84    ctx->NewState |= _NEW_VIEWPORT;
  85
  86 #if 1
  87    /* XXX remove this someday.  Currently the DRI drivers rely on
  88     * the WindowMap matrix being up to date in the driver's Viewport
  89     * and DepthRange functions.
  90     */
  91    _math_matrix_viewport(&ctx->Viewport._WindowMap,
  92                          ctx->Viewport.X, ctx->Viewport.Y,
  93                          ctx->Viewport.Width, ctx->Viewport.Height,
  94                          ctx->Viewport.Near, ctx->Viewport.Far,
  95                          ctx->DrawBuffer->_DepthMaxF);
  96 #endif
  97
  98    if (ctx->Driver.Viewport) {
  99       /* Many drivers will use this call to check for window size changes
 100        * and reallocate the z/stencil/accum/etc buffers if needed.
 101        */
 102       ctx->Driver.Viewport(ctx, x, y, width, height);
 103    }
 104 }
 105
 106
 107 /**
 108  * Called by glDepthRange
 109  *
 110  * \param nearval  specifies the Z buffer value which should correspond to
 111  *                 the near clip plane
 112  * \param farval  specifies the Z buffer value which should correspond to
 113  *                the far clip plane
 114  */
 115 void GLAPIENTRY
 116 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 117 {
 118    GET_CURRENT_CONTEXT(ctx);
 119
 120    FLUSH_VERTICES(ctx, 0);
 121
 122    if (MESA_VERBOSE&VERBOSE_API)
 123       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 124
 125    if (ctx->Viewport.Near == nearval &&
 126        ctx->Viewport.Far == farval)
 127       return;
 128
 129    ctx->Viewport.Near = (GLfloat) CLAMP(nearval, 0.0, 1.0);
 130    ctx->Viewport.Far = (GLfloat) CLAMP(farval, 0.0, 1.0);
 131    ctx->NewState |= _NEW_VIEWPORT;
 132
 133 #if 1
 134    /* XXX remove this someday.  Currently the DRI drivers rely on
 135     * the WindowMap matrix being up to date in the driver's Viewport
 136     * and DepthRange functions.
 137     */
 138    _math_matrix_viewport(&ctx->Viewport._WindowMap,
 139                          ctx->Viewport.X, ctx->Viewport.Y,
 140                          ctx->Viewport.Width, ctx->Viewport.Height,
 141                          ctx->Viewport.Near, ctx->Viewport.Far,
 142                          ctx->DrawBuffer->_DepthMaxF);
 143 #endif
 144
 145    if (ctx->Driver.DepthRange) {
 146       ctx->Driver.DepthRange(ctx, nearval, farval);
 147    }
 148 }
 149
 150 void GLAPIENTRY
 151 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 152 {
 153    _mesa_DepthRange(nearval, farval);
 154 }
 155
 156 /**
 157  * Initialize the context viewport attribute group.
 158  * \param ctx  the GL context.
 159  */
 160 void _mesa_init_viewport(struct gl_context *ctx)
 161 {
 162    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 163
 164    /* Viewport group */
 165    ctx->Viewport.X = 0;
 166    ctx->Viewport.Y = 0;
 167    ctx->Viewport.Width = 0;
 168    ctx->Viewport.Height = 0;
 169    ctx->Viewport.Near = 0.0;
 170    ctx->Viewport.Far = 1.0;
 171    _math_matrix_ctr(&ctx->Viewport._WindowMap);
 172
 173    _math_matrix_viewport(&ctx->Viewport._WindowMap, 0, 0, 0, 0,
 174                          0.0F, 1.0F, depthMax);
 175 }
 176
 177
 178 /**
 179  * Free the context viewport attribute group data.
 180  * \param ctx  the GL context.
 181  */
 182 void _mesa_free_viewport_data(struct gl_context *ctx)
 183 {
 184    _math_matrix_dtr(&ctx->Viewport._WindowMap);
 185 }
 186