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  * Update the viewport transformation matrix.  Depends on:
  38  *  - viewport pos/size
  39  *  - depthrange
  40  *  - window pos/size or FBO size
  41  */
  42 static void
  43 update_viewport( struct st_context *st )
  44 {
  45    GLcontext *ctx = st->ctx;
  46    GLfloat yScale, yBias;
  47
  48    /* _NEW_BUFFERS
  49     */
  50    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  51       yScale = -1;
  52       yBias = ctx->DrawBuffer->Height ;
  53    }
  54    else {
  55       yScale = 1.0;
  56       yBias = 0.0;
  57    }
  58
  59    /* _NEW_VIEWPORT
  60     */
  61    {
  62       GLfloat x = ctx->Viewport.X;
  63       GLfloat y = ctx->Viewport.Y;
  64       GLfloat z = ctx->Viewport.Near;
  65       GLfloat half_width = ctx->Viewport.Width / 2.0;
  66       GLfloat half_height = ctx->Viewport.Height / 2.0;
  67       GLfloat half_depth = (ctx->Viewport.Far - ctx->Viewport.Near) / 2.0;
  68       struct pipe_viewport_state vp;
  69
  70       vp.scale[0] = half_width;
  71       vp.scale[1] = half_height * yScale;
  72       vp.scale[2] = half_depth;
  73       vp.scale[3] = 1.0;
  74
  75       vp.translate[0] = half_width + x;
  76       vp.translate[1] = (half_height + y) * yScale + yBias;
  77       vp.translate[2] = half_depth + z;
  78       vp.translate[3] = 0.0;
  79
  80       if (memcmp(&vp, &st->state.viewport, sizeof(vp)) != 0) {
  81          st->state.viewport = vp;
  82          st->pipe->set_viewport_state(st->pipe, &vp);
  83       }
  84    }
  85 }
  86
  87
  88 const struct st_tracked_state st_update_viewport = {
  89    .name = "st_update_viewport",
  90    .dirty = {
  91       .mesa = _NEW_BUFFERS | _NEW_VIEWPORT,
  92       .st = 0,
  93    },
  94    .update = update_viewport
  95 };