UI: Widget: Replace geometry by fragment shader drawing

This means all the antiailasing is done inside the fragment shader.

We use a Signed Distance Field to draw the 2D rounded boxes. This ensure
the best quality for AA.

This reduce the averge Batch for widget to 16 verts instead of ~600 and
reduce overshading a lot.

Theme Emboss alpha and tria alpha needs to be changed after this refactor.

The shadow drawing is left unchanged and still use geometry.

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D7833

1 files changed, 3 insertions, 2 deletions

diff --git a/source/blender/editors/interface/interface_intern.h b/source/blender/editors/interface/interface_intern.h
index 6cd990ec2b0..fac78808a9a 100644
--- a/source/blender/editors/interface/interface_intern.h
+++ b/source/blender/editors/interface/interface_intern.h
@@ -848,6 +848,8 @@ typedef struct uiWidgetBaseParameters {
    * The absolute value itself is the discard factor.
    * Initialize value to 1.0.f if you don't want discard */
   float alpha_discard;
+  float tria_type;
+  float _pad[3];
 } uiWidgetBaseParameters;
 
 enum {
@@ -861,8 +863,7 @@ enum {
   ROUNDBOX_TRIA_MAX, /* don't use */
 };
 
-struct GPUBatch *ui_batch_roundbox_get(bool filled, bool antialiased);
-struct GPUBatch *ui_batch_roundbox_widget_get(int tria);
+struct GPUBatch *ui_batch_roundbox_widget_get(void);
 struct GPUBatch *ui_batch_roundbox_shadow_get(void);
 
 void ui_draw_anti_tria_rect(const rctf *rect, char dir, const float color[4]);