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### 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 #####
import bpy
import bgl
import math
import gpu
from gpu_extras.batch import batch_for_shader
from mathutils import Vector
if bpy.app.background: # ignore north line in background mode
def north_update(self, context):
pass
else:
vertex_shader = '''
uniform mat4 u_ViewProjectionMatrix;
in vec3 position;
flat out vec2 v_StartPos;
out vec4 v_VertPos;
void main()
{
vec4 pos = u_ViewProjectionMatrix * vec4(position, 1.0f);
gl_Position = pos;
v_StartPos = (pos / pos.w).xy;
v_VertPos = pos;
}
'''
fragment_shader = '''
uniform vec4 u_Color;
flat in vec2 v_StartPos;
in vec4 v_VertPos;
out vec4 FragColor;
uniform vec2 u_Resolution;
void main()
{
vec4 vertPos_2d = v_VertPos / v_VertPos.w;
vec2 dir = (vertPos_2d.xy - v_StartPos.xy) * u_Resolution;
float dist = length(dir);
if (step(sin(dist / 5.0f), 0.0) == 1) discard;
FragColor = u_Color;
}
'''
shader = gpu.types.GPUShader(vertex_shader, fragment_shader)
def draw_north_callback():
# ------------------------------------------------------------------
# Set up the compass needle using the current north offset angle
# less 90 degrees. This forces the unit circle to begin at the
# 12 O'clock instead of 3 O'clock position.
# ------------------------------------------------------------------
sun_props = bpy.context.scene.sun_pos_properties
color = (0.2, 0.6, 1.0, 0.7)
radius = 100
angle = -(sun_props.north_offset - math.pi / 2)
x = math.cos(angle) * radius
y = math.sin(angle) * radius
coords = Vector((x, y, 0)), Vector((0, 0, 0)) # Start & end of needle
batch = batch_for_shader(
shader, 'LINE_STRIP',
{"position": coords},
)
shader.bind()
matrix = bpy.context.region_data.perspective_matrix
shader.uniform_float("u_ViewProjectionMatrix", matrix)
shader.uniform_float("u_Resolution", (bpy.context.region.width, bpy.context.region.height))
shader.uniform_float("u_Color", color)
bgl.glLineWidth(2.0)
batch.draw(shader)
_handle = None
def north_update(self, context):
global _handle
if self.show_north and _handle is None:
_handle = bpy.types.SpaceView3D.draw_handler_add(draw_north_callback, (), 'WINDOW', 'POST_VIEW')
elif _handle is not None:
bpy.types.SpaceView3D.draw_handler_remove(_handle, 'WINDOW')
_handle = None
context.area.tag_redraw()
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