Clean up a little bit of API code. Fix an issue with missing operator. Port random semi complex shader.

test/night_time.ink

@@ -0,0 +1,78 @@
+p :: properties {
+	input_tex : Texture2D;
+	tex_sampler : Sampler;
+
+	hour_of_day : float;
+}
+
+VS_Input :: struct {
+	pos : float3 @position;
+	uv  : float2 @uv;
+}
+
+VS_Output :: struct {
+	pos : float4 @outposition;
+	uv  : float2 @uv;
+}
+
+vertex main :: (input : VS_Input) -> VS_Output {
+	output : VS_Output;
+	output.pos = float4(input.pos, 1.0);
+	output.uv  = input.uv;
+	return output;
+}
+
+apply_night :: (color : float4) -> float4 {
+	result := color;
+	result -= float4(0.3, 0.2, 0.0, 0.0);
+	result *= 0.8;
+
+	return result;
+}
+
+apply_twilight :: (color : float4) -> float4 {
+	result := color;
+	result += float4(0.2, -0.1, 0.1, 0.0);
+	result *= 0.9;
+
+	return result;
+}
+
+apply_morning :: (color : float4) -> float4 {
+	return color * 1.3;
+}
+
+apply_dawn :: (color : float4) -> float4 {
+	return color;
+}
+
+pixel main :: (input : VS_Output) -> float4 @outposition {
+	sampled_color : float4 = sample(p.input_tex, p.tex_sampler, input.uv);
+
+	t := 0.0;
+	a := float4(0, 0, 0, 0);
+	b := float4(0, 0, 0, 0);
+
+	if p.hour_of_day > 16 {
+        t = (p.hour_of_day - 16) / 6;
+        a = apply_twilight(sampled_color);
+        b = apply_night(sampled_color);
+    } else if p.hour_of_day > 12 {
+        t = (p.hour_of_day - 12) / 6;
+        a = sampled_color;
+        b = apply_twilight(sampled_color);
+    } else if p.hour_of_day > 6 {
+        t = (p.hour_of_day - 6) / 6;
+        a = apply_morning(sampled_color);
+        b = sampled_color;
+    } else if p.hour_of_day >= 0 {
+        t = p.hour_of_day / 6;
+        a = apply_night(sampled_color);
+        b = apply_morning(sampled_color);
+    }
+
+	return lerp(a, b, t);
+}
+
+
+