def geom_shader(view: View, gl_in: Sequence[GlGsIn],
vs_out: Sequence[VsOut]) -> Iterator[GsOut]:
triangle = Array3[vec2]
triangle[0] = viewport_to_screen_space(view.fb_size, gl_in[0].gl_position)
triangle[1] = viewport_to_screen_space(view.fb_size, gl_in[1].gl_position)
triangle[2] = viewport_to_screen_space(view.fb_size, gl_in[2].gl_position)
altitudes = vec3(triangle_2d_altitudes(triangle))
yield GsOut(gl_position=gl_in[0].gl_position,
altitudes=vec3(altitudes[0], 0, 0),
normal=vs_out[0].normal,
color=vs_out[0].color)
yield GsOut(gl_position=gl_in[1].gl_position,
altitudes=vec3(0, altitudes[1], 0),
normal=vs_out[1].normal,
color=vs_out[1].color)
yield GsOut(gl_position=gl_in[2].gl_position,
altitudes=vec3(0, 0, altitudes[2]),
normal=vs_out[2].normal,
color=vs_out[2].color)
end_primitive()
def geom_shader(view: View, gl_in: Sequence[GlGsIn],
vs_out: Sequence[VsOut]) -> Iterator[GsOut]:
triangle = Array3[vec2]
triangle[0] = viewport_to_screen_space(view.fb_size, gl_in[0].gl_position)
triangle[1] = viewport_to_screen_space(view.fb_size, gl_in[1].gl_position)
triangle[2] = viewport_to_screen_space(view.fb_size, gl_in[2].gl_position)
altitudes = vec3(triangle_2d_altitudes(triangle))
yield GsOut(gl_position=gl_in[0].gl_position,
altitudes=vec3(altitudes[0], 0, 0),
normal=vs_out[0].normal,
color=vs_out[0].color)
yield GsOut(gl_position=gl_in[1].gl_position,
altitudes=vec3(0, altitudes[1], 0),
normal=vs_out[1].normal,
color=vs_out[1].color)
yield GsOut(gl_position=gl_in[2].gl_position,
altitudes=vec3(0, 0, altitudes[2]),
normal=vs_out[2].normal,
color=vs_out[2].color)
end_primitive()
def triangle_2d_altitudes(triangle: Array3[vec2]) -> vec3:
ed0 = vec2(triangle[2] - triangle[1])
ed1 = vec2(triangle[2] - triangle[0])
ed2 = vec2(triangle[1] - triangle[0])
area = float(abs((ed1.x * ed2.y) - (ed1.y * ed2.x)))
return vec3(area / length(ed0), area / length(ed1), area / length(ed2))
def triangle_2d_altitudes(triangle: Array3[vec2]) -> vec3:
ed0 = vec2(triangle[2] - triangle[1])
ed1 = vec2(triangle[2] - triangle[0])
ed2 = vec2(triangle[1] - triangle[0])
area = float(abs((ed1.x * ed2.y) -
(ed1.y * ed2.x)))
return vec3(area / length(ed0),
area / length(ed1),
area / length(ed2))
class GsOut(ShaderInterface):
gl_position = vec4()
altitudes = vec3(noperspective)
normal = vec3()
color = vec4()
class VsOut(ShaderInterface):
gl_position = vec4()
normal = vec3()
color = vec4()
class VertAttrs(AttributeBlock):
vert_loc = vec3()
vert_nor = vec3()
vert_col = vec4()