add emission gbuffer attachment

res/shaders/main.glslf

@@ -1,6 +1,7 @@
 layout (location = 0) out vec4 f_color;
 layout (location = 1) out vec4 f_position;
 layout (location = 2) out vec4 f_normal;
+layout (location = 3) out vec4 f_emission;
 
 in float a_distance;
 in float a_fog;
@@ -12,6 +13,7 @@ in vec3 a_realnormal;
 in vec3 a_skyLight;
 in vec4 a_modelpos;
 in vec4 a_torchLight;
+in float a_emission;
 
 uniform sampler2D u_texture0;
 uniform samplerCube u_skybox;
@@ -47,8 +49,8 @@ void main() {
     vec3 fogColor = texture(u_skybox, a_dir).rgb;
     f_color = mix(f_color, vec4(fogColor, 1.0), a_fog);
 #endif
-
     f_color.a = alpha;
     f_position = vec4(a_position, 1.0);
     f_normal = vec4(a_normal, 1.0);
+    f_emission = vec4(a_emission);
 }