src/mesa/state_tracker/st_atom_viewport.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * 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
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "context.h"
  30 #include "colormac.h"
  31 #include "st_context.h"
  32 #include "pipe/p_context.h"
  33 #include "st_atom.h"
  34
  35
  36
  37
  38
  39 /**
  40  * Update the viewport transformation matrix.  Depends on:
  41  *  - viewport pos/size
  42  *  - depthrange
  43  *  - window pos/size or FBO size
  44  */
  45 static void update_viewport( struct st_context *st )
  46 {
  47    GLcontext *ctx = st->ctx;
  48    const GLframebuffer *DrawBuffer = ctx->DrawBuffer;
  49    GLfloat yScale = 1.0;
  50    GLfloat yBias = 0.0;
  51
  52    /* _NEW_BUFFERS
  53     */
  54    if (DrawBuffer) {
  55
  56 #if 0
  57       if (DrawBuffer->Name) {
  58          /* User created FBO */
  59          struct st_renderbuffer *irb
  60             = st_renderbuffer(DrawBuffer->_ColorDrawBuffers[0][0]);
  61          if (irb && !irb->RenderToTexture) {
  62             /* y=0=top */
  63             yScale = -1.0;
  64             yBias = irb->Base.Height;
  65          }
  66          else {
  67             /* y=0=bottom */
  68             yScale = 1.0;
  69             yBias = 0.0;
  70          }
  71       }
  72       else
  73       {
  74          /* window buffer, y=0=top */
  75          yScale = -1.0;
  76          yBias = DrawBuffer->Height;
  77       }
  78 #endif
  79    }
  80
  81    {
  82       /* _NEW_VIEWPORT
  83        */
  84       GLfloat x = ctx->Viewport.X;
  85       GLfloat y = ctx->Viewport.Y;
  86       GLfloat z = ctx->Viewport.Near;
  87       GLfloat half_width = ctx->Viewport.Width / 2.0;
  88       GLfloat half_height = ctx->Viewport.Height / 2.0;
  89       GLfloat half_depth = (ctx->Viewport.Far - ctx->Viewport.Near) / 2.0;
  90
  91       struct pipe_viewport_state vp;
  92
  93       vp.scale[0] = half_width;
  94       vp.scale[1] = half_height * yScale;
  95       vp.scale[2] = half_depth;
  96       vp.scale[3] = 1.0;
  97
  98       vp.translate[0] = (half_width + x);
  99       vp.translate[1] = (half_height + y) * yScale + yBias;
 100       vp.translate[2] = (half_depth + z);
 101       vp.translate[3] = 0.0;
 102
 103       if (memcmp(&vp, &st->state.viewport, sizeof(vp)) != 0) {
 104          st->state.viewport = vp;
 105          st->pipe->set_viewport_state(st->pipe, &vp);
 106       }
 107    }
 108 }
 109
 110
 111 const struct st_tracked_state st_update_viewport = {
 112    .dirty = {
 113       .mesa = _NEW_BUFFERS | _NEW_VIEWPORT,
 114       .st = 0,
 115    },
 116    .update = update_viewport
 117 };