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
  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
  51    if (MESA_VERBOSE & VERBOSE_API)
  52       _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
  53
  54    if (width < 0 || height < 0) {
  55       _mesa_error(ctx,  GL_INVALID_VALUE,
  56                    "glViewport(%d, %d, %d, %d)", x, y, width, height);
  57       return;
  58    }
  59
  60    _mesa_set_viewport(ctx, 0, x, y, width, height);
  61 }
  62
  63
  64 /**
  65  * Set new viewport parameters and update derived state (the _WindowMap
  66  * matrix).  Usually called from _mesa_Viewport().
  67  *
  68  * \param ctx GL context.
  69  * \param idx    Index of the viewport to be updated.
  70  * \param x, y coordinates of the lower left corner of the viewport rectangle.
  71  * \param width width of the viewport rectangle.
  72  * \param height height of the viewport rectangle.
  73  */
  74 void
  75 _mesa_set_viewport(struct gl_context *ctx, unsigned idx, GLint x, GLint y,
  76                     GLsizei width, GLsizei height)
  77 {
  78    /* clamp width and height to the implementation dependent range */
  79    width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
  80    height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
  81
  82    ctx->ViewportArray[idx].X = x;
  83    ctx->ViewportArray[idx].Width = width;
  84    ctx->ViewportArray[idx].Y = y;
  85    ctx->ViewportArray[idx].Height = height;
  86    ctx->NewState |= _NEW_VIEWPORT;
  87
  88 #if 1
  89    /* XXX remove this someday.  Currently the DRI drivers rely on
  90     * the WindowMap matrix being up to date in the driver's Viewport
  91     * and DepthRange functions.
  92     */
  93    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
  94                          ctx->ViewportArray[idx].X,
  95                          ctx->ViewportArray[idx].Y,
  96                          ctx->ViewportArray[idx].Width,
  97                          ctx->ViewportArray[idx].Height,
  98                          ctx->ViewportArray[idx].Near,
  99                          ctx->ViewportArray[idx].Far,
 100                          ctx->DrawBuffer->_DepthMaxF);
 101 #endif
 102
 103    if (ctx->Driver.Viewport) {
 104       /* Many drivers will use this call to check for window size changes
 105        * and reallocate the z/stencil/accum/etc buffers if needed.
 106        */
 107       ctx->Driver.Viewport(ctx);
 108    }
 109 }
 110
 111 static void
 112 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
 113                           GLclampd nearval, GLclampd farval)
 114 {
 115    if (ctx->ViewportArray[idx].Near == nearval &&
 116        ctx->ViewportArray[idx].Far == farval)
 117       return;
 118
 119    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
 120    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
 121    ctx->NewState |= _NEW_VIEWPORT;
 122
 123 #if 1
 124    /* XXX remove this someday.  Currently the DRI drivers rely on
 125     * the WindowMap matrix being up to date in the driver's Viewport
 126     * and DepthRange functions.
 127     */
 128    _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
 129                          ctx->ViewportArray[idx].X,
 130                          ctx->ViewportArray[idx].Y,
 131                          ctx->ViewportArray[idx].Width,
 132                          ctx->ViewportArray[idx].Height,
 133                          ctx->ViewportArray[idx].Near,
 134                          ctx->ViewportArray[idx].Far,
 135                          ctx->DrawBuffer->_DepthMaxF);
 136 #endif
 137 }
 138
 139 void
 140 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
 141                       GLclampd nearval, GLclampd farval)
 142 {
 143    set_depth_range_no_notify(ctx, idx, nearval, farval);
 144
 145    if (ctx->Driver.DepthRange)
 146       ctx->Driver.DepthRange(ctx);
 147 }
 148
 149 /**
 150  * Called by glDepthRange
 151  *
 152  * \param nearval  specifies the Z buffer value which should correspond to
 153  *                 the near clip plane
 154  * \param farval  specifies the Z buffer value which should correspond to
 155  *                the far clip plane
 156  */
 157 void GLAPIENTRY
 158 _mesa_DepthRange(GLclampd nearval, GLclampd farval)
 159 {
 160    GET_CURRENT_CONTEXT(ctx);
 161
 162    FLUSH_VERTICES(ctx, 0);
 163
 164    if (MESA_VERBOSE&VERBOSE_API)
 165       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
 166
 167    set_depth_range_no_notify(ctx, 0, nearval, farval);
 168
 169    if (ctx->Driver.DepthRange) {
 170       ctx->Driver.DepthRange(ctx);
 171    }
 172 }
 173
 174 void GLAPIENTRY
 175 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 176 {
 177    _mesa_DepthRange(nearval, farval);
 178 }
 179
 180 /**
 181  * Initialize the context viewport attribute group.
 182  * \param ctx  the GL context.
 183  */
 184 void _mesa_init_viewport(struct gl_context *ctx)
 185 {
 186    GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
 187
 188    /* Viewport group */
 189    ctx->ViewportArray[0].X = 0;
 190    ctx->ViewportArray[0].Y = 0;
 191    ctx->ViewportArray[0].Width = 0;
 192    ctx->ViewportArray[0].Height = 0;
 193    ctx->ViewportArray[0].Near = 0.0;
 194    ctx->ViewportArray[0].Far = 1.0;
 195    _math_matrix_ctr(&ctx->ViewportArray[0]._WindowMap);
 196
 197    _math_matrix_viewport(&ctx->ViewportArray[0]._WindowMap, 0, 0, 0, 0,
 198                          0.0F, 1.0F, depthMax);
 199 }
 200
 201
 202 /**
 203  * Free the context viewport attribute group data.
 204  * \param ctx  the GL context.
 205  */
 206 void _mesa_free_viewport_data(struct gl_context *ctx)
 207 {
 208    _math_matrix_dtr(&ctx->ViewportArray[0]._WindowMap);
 209 }
 210