Changeset 2311
 Timestamp:
 Feb 1, 2013, 3:48:54 PM (6 years ago)
 File:

 1 edited
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trunk/tutorial/04_texture.lolfx
r2197 r2311 75 75 } 76 76 77 [vert.hlsl] 78 79 void main(float2 in_Position : POSITION, 80 out float4 out_Position : POSITION, 81 out float4 pass_Position : TEXCOORD0) 82 { 83 pass_Position = float4(0.5 * in_Position + 0.5, 0.0, 1.0); 84 out_Position = float4(in_Position, 0.5, 1.0); 85 } 86 87 [frag.hlsl] 88 89 float segdist(float2 p1, float2 p2, float2 a) 90 { 91 float d = max(1e10, dot(p2  p1, p2  p1)); 92 float t = clamp(dot(a  p1, p2  p1) / d, 0.0, 1.0); 93 return distance(a, lerp(p1, p2, t)); 94 } 95 96 void main(in float4 pass_Position : TEXCOORD0, 97 uniform sampler2D u_Texture, 98 out float4 out_FragColor : COLOR) 99 { 100 float width = 800.0; 101 float height = 600.0; 102 float texture_width = 256.0; 103 float line_width = 1.2; 104 float dot_size = 1.0; 105 float4 delta = float4(1.0 / texture_width, 0.0, 106 2.0 / texture_width, 0.0); 107 108 float2 p = pass_Position.xy; 109 float2 tc = float2(floor(p.x * texture_width) / texture_width, p.y); 110 float t = p.x * texture_width  floor(p.x * texture_width); 111 float4 c; 112 c[0] = tex2D(u_Texture, tc  delta.xy).x; 113 c[1] = tex2D(u_Texture, tc).x; 114 c[2] = tex2D(u_Texture, tc + delta.xy).x; 115 c[3] = tex2D(u_Texture, tc + delta.zw).x; 116 117 /* Find the 4 closest points in screen space */ 118 float2 p0 = float2((tc.x  delta.x) * width, c[0] * height); 119 float2 p1 = float2((tc.x ) * width, c[1] * height); 120 float2 p2 = float2((tc.x + delta.x) * width, c[2] * height); 121 float2 p3 = float2((tc.x + delta.z) * width, c[3] * height); 122 float2 a = float2(p.x * width, p.y * height); 123 124 /* Compute distance to segments */ 125 float d = segdist(p0, p1, a); 126 d = min(d, segdist(p1, p2, a)); 127 d = min(d, segdist(p2, p3, a)); 128 129 /* Compute distance to dots */ 130 d = min(d, length(a  p0)  dot_size); 131 d = min(d, length(a  p1)  dot_size); 132 d = min(d, length(a  p2)  dot_size); 133 d = min(d, length(a  p3)  dot_size); 134 135 /* Add line width */ 136 float lum = clamp(line_width  d, 0.0, 1.0); 137 138 /* Compensate for sRGB */ 139 lum = pow(1.0  lum, 1.0 / 2.4); 140 141 /* Choose some funny colours */ 142 out_FragColor = float4(lerp(p.x, 1.0, lum), lum, lum, 1.0); 143 } 144
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