Testing without sokol_gp.h

src/shaders/base.glsl

@@ -0,0 +1,60 @@
+@block common
+struct cell
+{
+    vec2 pos;
+};
+vec3 color(int i)
+{
+    float r = ((i >>  0) & 0xff)/255.0f;
+    float g = ((i >>  8) & 0xff)/255.0f;
+    float b = ((i >> 16) & 0xff)/255.0f;
+    return vec3(r, g, b);
+}
+@end
+
+@vs vs
+@include_block common
+layout(binding = 0) uniform vs_uniform {
+    float radius;
+};
+
+layout(location = 0) in vec2 in_quad;
+layout(location = 1) out vec2 _quad;
+layout(location = 2) out vec2 _centroid;
+layout(location = 3) flat out vec3 _color;
+
+layout(binding = 0) readonly buffer vs_ssbo
+{
+    cell cells[];
+};
+
+void main()
+{
+    _centroid = cells[gl_InstanceIndex].pos;
+    _color = color(gl_InstanceIndex);
+    _quad = radius * in_quad + _centroid;
+    gl_Position = vec4(_quad, 0.0, 1.0);
+}
+@end
+
+@fs fs
+@include_block common
+
+layout(binding = 1) uniform fs_uniform {
+    float radius;
+};
+
+layout(location = 1) in vec2 _quad;
+layout(location = 2) in vec2 _centroid;
+layout(location = 3) flat in vec3 _color;
+layout(location = 4) out vec4 frag_color;
+
+void main()
+{
+    gl_FragDepth = length(_quad - _centroid);
+    if(gl_FragDepth > radius) discard;
+    frag_color = vec4(_color, 1.0);
+}
+@end
+
+@program base vs fs