Clément Foucault
a3cb9c8238
This method is a bit more optimized than the very first one because it does not rely on the adjacent faces properties. That said it's still a bit slower than the per vertex method.
87 lines
2.2 KiB
GLSL
87 lines
2.2 KiB
GLSL
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/* This shader is only used for intel GPU where the Geom shader is faster
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* than doing everything thrice in the vertex shader. */
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layout(triangles) in;
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layout(triangle_strip, max_vertices = 3) out;
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uniform vec2 wireStepParam;
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in vec2 ssPos[];
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in float facingOut[];
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flat out vec3 ssVec0;
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flat out vec3 ssVec1;
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flat out vec3 ssVec2;
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out float facing;
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#ifdef LIGHT_EDGES
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in vec3 obPos[];
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in vec3 vNor[];
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in float forceEdge[];
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flat out vec3 edgeSharpness;
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#endif
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#define NO_EDGE vec3(10000.0);
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/* TODO(fclem) remove code duplication. */
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vec3 compute_vec(vec2 v0, vec2 v1)
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{
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vec2 v = normalize(v1 - v0);
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v = vec2(-v.y, v.x);
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return vec3(v, -dot(v, v0));
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}
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vec3 get_edge_normal(vec3 n1, vec3 n2, vec3 edge)
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{
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edge = normalize(edge);
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vec3 n = n1 + n2;
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float p = dot(edge, n);
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return normalize(n - p * edge);
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}
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float get_edge_sharpness(vec3 fnor, vec3 vnor)
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{
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float sharpness = abs(dot(fnor, vnor));
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return smoothstep(wireStepParam.x, wireStepParam.y, sharpness);
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}
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void main(void)
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{
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vec3 facings = vec3(facingOut[0], facingOut[1], facingOut[2]);
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bvec3 do_edge = greaterThan(abs(facings), vec3(1.0));
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facings = fract(facings) - clamp(-sign(facings), 0.0, 1.0);
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ssVec0 = do_edge.x ? compute_vec(ssPos[0], ssPos[1]) : NO_EDGE;
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ssVec1 = do_edge.y ? compute_vec(ssPos[1], ssPos[2]) : NO_EDGE;
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ssVec2 = do_edge.z ? compute_vec(ssPos[2], ssPos[0]) : NO_EDGE;
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#ifdef LIGHT_EDGES
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vec3 edges[3];
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edges[0] = obPos[1] - obPos[0];
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edges[1] = obPos[2] - obPos[1];
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edges[2] = obPos[0] - obPos[2];
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vec3 fnor = normalize(cross(edges[0], -edges[2]));
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edgeSharpness.x = get_edge_sharpness(fnor, get_edge_normal(vNor[0], vNor[1], edges[0]));
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edgeSharpness.y = get_edge_sharpness(fnor, get_edge_normal(vNor[1], vNor[2], edges[1]));
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edgeSharpness.z = get_edge_sharpness(fnor, get_edge_normal(vNor[2], vNor[0], edges[2]));
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edgeSharpness.x = (forceEdge[0] == 1.0) ? 1.0 : edgeSharpness.x;
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edgeSharpness.y = (forceEdge[1] == 1.0) ? 1.0 : edgeSharpness.y;
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edgeSharpness.z = (forceEdge[2] == 1.0) ? 1.0 : edgeSharpness.z;
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#endif
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gl_Position = gl_in[0].gl_Position;
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facing = facings.x;
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EmitVertex();
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gl_Position = gl_in[1].gl_Position;
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facing = facings.y;
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EmitVertex();
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gl_Position = gl_in[2].gl_Position;
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facing = facings.z;
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EmitVertex();
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EndPrimitive();
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}
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