mesa: Refactor viewport transform computation.

[mesa.git] / src / mesa / state_tracker / st_atom_viewport.c

diff --git a/src/mesa/state_tracker/st_atom_viewport.c b/src/mesa/state_tracker/st_atom_viewport.c
index d10f1840df6ac3db0210a04d7fc07a2ee8f3c627..5b992084bd5c8ef6951e8cecf69642eb6a73a986 100644 (file)
--- a/src/mesa/state_tracker/st_atom_viewport.c
+++ b/src/mesa/state_tracker/st_atom_viewport.c
@@ -1,6 +1,6 @@
 /**************************************************************************
  * 
- * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2007 VMware, Inc.
  * All Rights Reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a
@@ -18,7 +18,7 @@
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
- * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
@@ -27,6 +27,7 @@
 
 
 #include "main/context.h"
+#include "main/viewport.h"
 #include "st_context.h"
 #include "st_atom.h"
 #include "pipe/p_context.h"
@@ -43,40 +44,43 @@ update_viewport( struct st_context *st )
 {
    struct gl_context *ctx = st->ctx;
    GLfloat yScale, yBias;
-
+   int i;
    /* _NEW_BUFFERS
     */
    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
+      /* Drawing to a window.  The corresponding gallium surface uses
+       * Y=0=TOP but OpenGL is Y=0=BOTTOM.  So we need to invert the viewport.
+       */
       yScale = -1;
       yBias = (GLfloat)ctx->DrawBuffer->Height;
    }
    else {
+      /* Drawing to an FBO where Y=0=BOTTOM, like OpenGL - don't invert */
       yScale = 1.0;
       yBias = 0.0;
    }
 
    /* _NEW_VIEWPORT 
     */
+   for (i = 0; i < ctx->Const.MaxViewports; i++)
    {
-      GLfloat x = (GLfloat)ctx->Viewport.X;
-      GLfloat y = (GLfloat)ctx->Viewport.Y;
-      GLfloat z = ctx->Viewport.Near;
-      GLfloat half_width = (GLfloat)ctx->Viewport.Width * 0.5f;
-      GLfloat half_height = (GLfloat)ctx->Viewport.Height * 0.5f;
-      GLfloat half_depth = (GLfloat)(ctx->Viewport.Far - ctx->Viewport.Near) * 0.5f;
-      
-      st->state.viewport.scale[0] = half_width;
-      st->state.viewport.scale[1] = half_height * yScale;
-      st->state.viewport.scale[2] = half_depth;
-      st->state.viewport.scale[3] = 1.0;
+      double scale[3], translate[3];
+      _mesa_get_viewport_xform(ctx, i, scale, translate);
 
-      st->state.viewport.translate[0] = half_width + x;
-      st->state.viewport.translate[1] = (half_height + y) * yScale + yBias;
-      st->state.viewport.translate[2] = half_depth + z;
-      st->state.viewport.translate[3] = 0.0;
+      st->state.viewport[i].scale[0] = scale[0];
+      st->state.viewport[i].scale[1] = scale[1] * yScale;
+      st->state.viewport[i].scale[2] = scale[2];
+      st->state.viewport[i].scale[3] = 1.0;
 
-      cso_set_viewport(st->cso_context, &st->state.viewport);
+      st->state.viewport[i].translate[0] = translate[0];
+      st->state.viewport[i].translate[1] = translate[1] * yScale + yBias;
+      st->state.viewport[i].translate[2] = translate[2];
+      st->state.viewport[i].translate[3] = 0.0;
    }
+
+   cso_set_viewport(st->cso_context, &st->state.viewport[0]);
+   if (ctx->Const.MaxViewports > 1)
+      st->pipe->set_viewport_states(st->pipe, 1, ctx->Const.MaxViewports - 1, &st->state.viewport[1]);
 }