83 lines
1.5 KiB
GLSL
83 lines
1.5 KiB
GLSL
// https://anirban-karchaudhuri.medium.com/edge-detection-methods-comparison-9e4b75a9bf87
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//!HOOK OUTPUT
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//!BIND HOOKED
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//!DESC edge detection
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#define tex HOOKED_texOff
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const mat3 prewitt_x = mat3(
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1.0, 0.0, -1.0,
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1.0, 0.0, -1.0,
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1.0, 0.0, -1.0
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);
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const mat3 prewitt_y = mat3(
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1.0, 1.0, 1.0,
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0.0, 0.0, 0.0,
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-1.0, -1.0, -1.0
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);
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const mat3 sobel_x = mat3(
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1.0, 0.0, -1.0,
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2.0, 0.0, -2.0,
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1.0, 0.0, -1.0
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);
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const mat3 sobel_y = mat3(
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1.0, 2.0, 1.0,
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0.0, 0.0, 0.0,
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-1.0, -2.0, -1.0
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);
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const mat3 laplacian_p = mat3(
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0.0, 1.0, 0.0,
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1.0, -4.0, 1.0,
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0.0, 1.0, 0.0
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);
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const mat3 laplacian_n = mat3(
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0.0, -1.0, 0.0,
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-1.0, 4.0, -1.0,
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0.0, -1.0, 0.0
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);
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const float base = 0.0;
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const uvec2 k_size = uvec2(3, 3);
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const vec2 k_size_h = vec2(k_size / 2);
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vec3 conv(mat3 k) {
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vec3 x = vec3(base);
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for (uint i = 0; i < k_size.x; i++)
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for (uint j = 0; j < k_size.y; j++)
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x += tex(vec2(j, i) - k_size_h).rgb * k[i][j];
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return x;
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}
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vec3 prewitt() {
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vec3 x = conv(prewitt_x);
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vec3 y = conv(prewitt_y);
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vec3 g = abs(sqrt(x * x + y * y));
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return g;
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}
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vec3 sobel() {
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vec3 x = conv(sobel_x);
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vec3 y = conv(sobel_y);
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vec3 g = abs(sqrt(x * x + y * y));
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return g;
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}
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vec3 laplacian() {
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vec3 x = conv(laplacian_p);
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return x;
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}
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vec4 hook() {
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vec4 color = vec4(vec3(0.0), 1.0);
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color.rgb = laplacian();
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return color;
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}
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