src/mesa/state_tracker/st_atom_viewport.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   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 VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  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 "main/context.h"
  30 #include "main/viewport.h"
  31 #include "st_context.h"
  32 #include "st_atom.h"
  33 #include "pipe/p_context.h"
  34 #include "cso_cache/cso_context.h"
  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    struct gl_context *ctx = st->ctx;
  46    GLfloat yScale, yBias;
  47    unsigned i;
  48    /* _NEW_BUFFERS
  49     */
  50    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  51       /* Drawing to a window.  The corresponding gallium surface uses
  52        * Y=0=TOP but OpenGL is Y=0=BOTTOM.  So we need to invert the viewport.
  53        */
  54       yScale = -1;
  55       yBias = (GLfloat)ctx->DrawBuffer->Height;
  56    }
  57    else {
  58       /* Drawing to an FBO where Y=0=BOTTOM, like OpenGL - don't invert */
  59       yScale = 1.0;
  60       yBias = 0.0;
  61    }
  62
  63    /* _NEW_VIEWPORT
  64     */
  65    for (i = 0; i < ctx->Const.MaxViewports; i++)
  66    {
  67       float scale[3], translate[3];
  68       _mesa_get_viewport_xform(ctx, i, scale, translate);
  69
  70       st->state.viewport[i].scale[0] = scale[0];
  71       st->state.viewport[i].scale[1] = scale[1] * yScale;
  72       st->state.viewport[i].scale[2] = scale[2];
  73
  74       st->state.viewport[i].translate[0] = translate[0];
  75       st->state.viewport[i].translate[1] = translate[1] * yScale + yBias;
  76       st->state.viewport[i].translate[2] = translate[2];
  77    }
  78
  79    cso_set_viewport(st->cso_context, &st->state.viewport[0]);
  80    if (ctx->Const.MaxViewports > 1)
  81       st->pipe->set_viewport_states(st->pipe, 1, ctx->Const.MaxViewports - 1, &st->state.viewport[1]);
  82 }
  83
  84
  85 const struct st_tracked_state st_update_viewport = {
  86    {                                                    /* dirty */
  87       _NEW_BUFFERS | _NEW_VIEWPORT,                     /* mesa */
  88       0,                                                /* st */
  89    },
  90    update_viewport                                      /* update */
  91 };