Mindustry/core/assets/shaders/outline.fragment
2018-11-16 21:33:10 -05:00

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#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
#define SPACE 2.0
uniform sampler2D u_texture;
uniform vec4 u_color;
uniform vec2 u_texsize;
varying vec4 v_color;
varying vec2 v_texCoord;
void main() {
vec2 v = vec2(1.0/u_texsize.x, 1.0/u_texsize.y);
vec4 c = texture2D(u_texture, v_texCoord.xy);
gl_FragColor = mix(c * v_color, u_color,
(1.0-step(0.1, texture2D(u_texture, v_texCoord.xy).a)) *
step(0.1,
//cardinals
texture2D(u_texture, v_texCoord.xy + vec2(0, SPACE) * v).a +
texture2D(u_texture, v_texCoord.xy + vec2(0, -SPACE) * v).a +
texture2D(u_texture, v_texCoord.xy + vec2(SPACE, 0) * v).a +
texture2D(u_texture, v_texCoord.xy + vec2(-SPACE, 0) * v).a +
//cardinal edges
texture2D(u_texture, v_texCoord.xy + vec2(SPACE, SPACE) * v).a +
texture2D(u_texture, v_texCoord.xy + vec2(SPACE, -SPACE) * v).a +
texture2D(u_texture, v_texCoord.xy + vec2(-SPACE, SPACE) * v).a +
texture2D(u_texture, v_texCoord.xy + vec2(-SPACE, -SPACE) * v).a +
//cardinals * 2
texture2D(u_texture, v_texCoord.xy + vec2(0, SPACE) * v*2.0).a +
texture2D(u_texture, v_texCoord.xy + vec2(0, -SPACE) * v*2.0).a +
texture2D(u_texture, v_texCoord.xy + vec2(SPACE, 0) * v*2.0).a +
texture2D(u_texture, v_texCoord.xy + vec2(-SPACE, 0) * v*2.0).a
));
}