gallium: move the test for bypass_vs into the vs_XXX_run() functions

Also:
1. Added an identity_viewport flag to skip viewport transformation when it
has no effect.  Might also add an explicit bypass_viewport flag someday.
2. Separate the code for computing clip codes and doing the viewport transform.
Predicate them separately.
Note: even if bypass_vs is set, we still look at the shader to determine the
number of inputs and outputs.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 10bf9f54c1..d0d5f66b37 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -228,6 +228,14 @@ void draw_set_viewport_state( struct draw_context *draw,
 {
    draw_do_flush( draw, DRAW_FLUSH_STATE_CHANGE );
    draw->viewport = *viewport; /* struct copy */
+   draw->identity_viewport = (viewport->scale[0] == 1.0f &&
+                              viewport->scale[1] == 1.0f &&
+                              viewport->scale[2] == 1.0f &&
+                              viewport->scale[3] == 1.0f &&
+                              viewport->translate[0] == 0.0f &&
+                              viewport->translate[1] == 0.0f &&
+                              viewport->translate[2] == 0.0f &&
+                              viewport->translate[3] == 0.0f);
 }