From 50d6f63fb28c82a35e68914fe941b685d26f6e89 Mon Sep 17 00:00:00 2001 From: Dan Goodliffe Date: Wed, 23 Nov 2022 19:07:18 +0000 Subject: Add rendering support for point lights --- gfx/gl/shaders/pointLight.gs | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 gfx/gl/shaders/pointLight.gs (limited to 'gfx/gl/shaders/pointLight.gs') diff --git a/gfx/gl/shaders/pointLight.gs b/gfx/gl/shaders/pointLight.gs new file mode 100644 index 0000000..2bd71e9 --- /dev/null +++ b/gfx/gl/shaders/pointLight.gs @@ -0,0 +1,44 @@ +#version 330 core +#extension GL_ARB_enhanced_layouts : enable +#extension GL_ARB_shading_language_420pack : enable + +const int maxv = 128; +const int maxarcs = (maxv / 2) - 1; +const int minarcs = 10; +const float tau = radians(360); +const float scale = 150; +uniform ivec4 viewPort; + +in vec3 centre[]; +in float size[]; +layout(points) in; + +layout(triangle_strip, max_vertices = maxv) out; +out vec3 geo_centre; + +void +doSeg(float arc, vec2 radius) +{ + gl_Position = gl_in[0].gl_Position; + geo_centre = centre[0]; + EmitVertex(); + + const vec2 off = vec2(cos(arc), sin(arc)) * radius; + gl_Position.xy = gl_in[0].gl_Position.xy + off; + geo_centre = centre[0]; + EmitVertex(); +} + +void +main() +{ + const vec2 display = viewPort.zw; + const vec2 ratio = vec2(1, display.x / display.y); + const vec2 radius = (size[0] * ratio * scale) / gl_in[0].gl_Position.w; + const float step = tau / clamp(radius.x, minarcs, maxarcs); + for (float arc = 0; arc < tau; arc += step) { + doSeg(arc, radius); + } + doSeg(tau, radius); + EndPrimitive(); +} -- cgit v1.2.3