mesa: Refactor viewport transform computation.

This is for preparation of ARB_clip_control.

v3:
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Reviewed-by: Brian Paul <[email protected]>
Signed-off-by: Mathias Froehlich <[email protected]>

1 files changed, 9 insertions, 17 deletions

diff --git a/src/mesa/drivers/dri/i915/i915_state.c b/src/mesa/drivers/dri/i915/i915_state.c
index f31b271500f..f9aecba2327 100644
--- a/src/mesa/drivers/dri/i915/i915_state.c
+++ b/src/mesa/drivers/dri/i915/i915_state.c
@@ -34,6 +34,7 @@
 #include "main/dd.h"
 #include "main/state.h"
 #include "main/stencil.h"
+#include "main/viewport.h"
 #include "tnl/tnl.h"
 #include "tnl/t_context.h"
 
@@ -401,26 +402,17 @@ void
 intelCalcViewport(struct gl_context * ctx)
 {
    struct intel_context *intel = intel_context(ctx);
+   double scale[3], translate[3];
+
+   _mesa_get_viewport_xform(ctx, 0, scale, translate);
 
    if (_mesa_is_winsys_fbo(ctx->DrawBuffer)) {
-      _math_matrix_viewport(&intel->ViewportMatrix,
-			    ctx->ViewportArray[0].X,
-			    ctx->DrawBuffer->Height - ctx->ViewportArray[0].Y,
-			    ctx->ViewportArray[0].Width,
-			    -ctx->ViewportArray[0].Height,
-			    ctx->ViewportArray[0].Near,
-			    ctx->ViewportArray[0].Far,
-			    1.0);
-   } else {
-      _math_matrix_viewport(&intel->ViewportMatrix,
-			    ctx->ViewportArray[0].X,
-			    ctx->ViewportArray[0].Y,
-			    ctx->ViewportArray[0].Width,
-			    ctx->ViewportArray[0].Height,
-			    ctx->ViewportArray[0].Near,
-			    ctx->ViewportArray[0].Far,
-			    1.0);
+      scale[1] = -scale[1];
+      translate[1] = ctx->DrawBuffer->Height - translate[1];
    }
+
+   _math_matrix_viewport(&intel->ViewportMatrix,
+                         scale, translate, 1.0);
 }