【Defold】セピア調シェーダー

uniform highp mat4 view_proj;
// positions are in world space
attribute highp vec4 position;
attribute mediump vec2 texcoord0;
varying mediump vec2 var_texcoord0;
void main()
{
	gl_Position = view_proj * vec4(position.xyz, 1.0);
	var_texcoord0 = texcoord0;
}

varying mediump vec2 var_texcoord0;
uniform lowp sampler2D texture_sampler;
uniform lowp vec4 tint;
const vec3 monochromeScale = vec3(0.298912, 0.586611, 0.114478);
const vec3 sepiaScale = vec3(1.07, 0.74, 0.43);
void main()
{
	// Pre-multiply alpha since all runtime textures already are
	lowp vec4 tint_pm = vec4(tint.xyz * tint.w, tint.w);
	vec4 sampleColor = texture2D(texture_sampler, var_texcoord0.xy) * tint_pm;
	float grayColor = dot(sampleColor.rgb, monochromeScale);
	vec3 monoColor = vec3(grayColor) * sepiaScale; 
	sampleColor = vec4(monoColor, 1.0);
	gl_FragColor = sampleColor;
}