Add `smoothstep`

core/math/linalg/glsl/linalg_glsl.odin

@@ -769,6 +769,31 @@ step_dvec2 :: proc "c" (edge, x: dvec2) -> dvec2 { return {step(edge.x, x.x), st
 step_dvec3 :: proc "c" (edge, x: dvec3) -> dvec3 { return {step(edge.x, x.x), step(edge.y, x.y), step(edge.z, x.z)} }
 step_dvec4 :: proc "c" (edge, x: dvec4) -> dvec4 { return {step(edge.x, x.x), step(edge.y, x.y), step(edge.z, x.z), step(edge.w, x.w)} }
 
+smoothstep :: proc{
+	smoothstep_f32,
+	smoothstep_f64,
+	smoothstep_vec2,
+	smoothstep_vec3,
+	smoothstep_vec4,
+	smoothstep_dvec2,
+	smoothstep_dvec3,
+	smoothstep_dvec4,
+}
+smoothstep_f32 :: proc "c" (edge0, edge1, x: f32) -> f32 { 
+	y := clamp(((x-edge0) / (edge1 - edge0)), 0, 1)
+	return y * y * (3 - 2*y)
+}
+smoothstep_f64 :: proc "c" (edge0, edge1, x: f64) -> f64 { 
+	y := clamp(((x-edge0) / (edge1 - edge0)), 0, 1)
+	return y * y * (3 - 2*y)
+}
+smoothstep_vec2  :: proc "c" (edge0, edge1, x: vec2) -> vec2   { return {smoothstep(edge0.x, edge1.x, x.x), smoothstep(edge0.y, edge1.y, x.y)} }
+smoothstep_vec3  :: proc "c" (edge0, edge1, x: vec3) -> vec3   { return {smoothstep(edge0.x, edge1.x, x.x), smoothstep(edge0.y, edge1.y, x.y), smoothstep(edge0.z, edge1.z, x.z)} }
+smoothstep_vec4  :: proc "c" (edge0, edge1, x: vec4) -> vec4   { return {smoothstep(edge0.x, edge1.x, x.x), smoothstep(edge0.y, edge1.y, x.y), smoothstep(edge0.z, edge1.z, x.z), smoothstep(edge0.w, edge1.w, x.w)} }
+smoothstep_dvec2 :: proc "c" (edge0, edge1, x: dvec2) -> dvec2 { return {smoothstep(edge0.x, edge1.x, x.x), smoothstep(edge0.y, edge1.y, x.y)} }
+smoothstep_dvec3 :: proc "c" (edge0, edge1, x: dvec3) -> dvec3 { return {smoothstep(edge0.x, edge1.x, x.x), smoothstep(edge0.y, edge1.y, x.y), smoothstep(edge0.z, edge1.z, x.z)} }
+smoothstep_dvec4 :: proc "c" (edge0, edge1, x: dvec4) -> dvec4 { return {smoothstep(edge0.x, edge1.x, x.x), smoothstep(edge0.y, edge1.y, x.y), smoothstep(edge0.z, edge1.z, x.z), smoothstep(edge0.w, edge1.w, x.w)} }
+
 
 abs :: proc{
 	abs_i32,