From f606ee7637eb26e749bc5c9f4bc914bcfba64ee6 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Thu, 25 Oct 2018 21:04:38 +1100
Subject: [PATCH] PyAPI: initial gpu_extras module (circle drawing utility)

---
 .../scripts/modules/gpu_extras/__init__.py    | 21 ++++++++++
 release/scripts/modules/gpu_extras/presets.py | 42 +++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 release/scripts/modules/gpu_extras/__init__.py
 create mode 100644 release/scripts/modules/gpu_extras/presets.py

diff --git a/release/scripts/modules/gpu_extras/__init__.py b/release/scripts/modules/gpu_extras/__init__.py
new file mode 100644
index 00000000000..221c7e2da58
--- /dev/null
+++ b/release/scripts/modules/gpu_extras/__init__.py
@@ -0,0 +1,21 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ***** END GPL LICENSE BLOCK *****
+
+__all__ = (
+    "presets",
+)
diff --git a/release/scripts/modules/gpu_extras/presets.py b/release/scripts/modules/gpu_extras/presets.py
new file mode 100644
index 00000000000..444e3ea24d0
--- /dev/null
+++ b/release/scripts/modules/gpu_extras/presets.py
@@ -0,0 +1,42 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ***** END GPL LICENSE BLOCK *****
+
+def draw_circle_2d(position, color, radius, segments):
+    from math import sin, cos, pi
+    import gpu
+    from gpu.types import (
+        GPUBatch,
+        GPUVertBuf,
+        GPUVertFormat,
+    )
+
+    with gpu.matrix.push_pop():
+        gpu.matrix.translate(position)
+        gpu.matrix.scale_uniform(radius)
+        seg = 32
+        mul = (1.0 / (seg - 1)) * (pi * 2)
+        verts = [(sin(i * mul), cos(i * mul)) for i in range(seg)]
+        fmt = GPUVertFormat(format=[])
+        pos_id = fmt.attr_add(id="pos", comp_type='F32', len=2, fetch_mode='FLOAT')
+        vbo = GPUVertBuf(len=len(verts), format=fmt)
+        vbo.attr_fill(id=pos_id, data=verts)
+        batch = GPUBatch(type='LINE_STRIP', buf=vbo)
+        shader = gpu.shader.from_builtin('2D_UNIFORM_COLOR')
+        batch.program_set(shader)
+        shader.uniform_float("color", color)
+        batch.draw()