Changeset 2133 for trunk/tutorial/04_texture.lolfx
 Timestamp:
 Dec 7, 2012, 12:19:22 AM (9 years ago)
 File:

 1 edited
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trunk/tutorial/04_texture.lolfx
r2050 r2133 26 26 } 27 27 28 float point2segment(vec2 p1, vec2 p2, vec2 a) 29 { 30 float l2 = dot(p2  p1, p2  p1); 31 if (l2 == 0.0) 32 return distance(a, p1); 33 float t = dot(a  p1, p2  p1) / l2; 34 if (t < 0.0) 35 return distance(a, p1); 36 else if (t > 1.0) 37 return distance(a, p2); 38 vec2 proj = p1 + t * (p2  p1); 39 return distance(a, proj); 40 } 41 42 28 43 void main(void) 29 44 { 45 float width = 800.0; 46 float height = 600.0; 47 float line_width = 2.0; 48 30 49 vec2 t = pass_Position.xy; 31 vec4 c0 = texture2D(u_Texture, t); 32 float f = rand(pass_Position.xy, 12345.67); 50 vec2 tc1 = floor(t * 128.0) / 128.0; 51 vec2 tc2 = tc1 + vec2(1.0, 1.0) / 128.0; 52 vec2 tc0 = tc1  vec2(1.0, 1.0) / 128.0; 53 vec2 tc3 = tc2 + vec2(1.0, 1.0) / 128.0; 33 54 34 if (t.y > c0.x) 35 { 36 /* Sky */ 37 float val = min(t.y * 2.0, 1.0); 38 if (f > 0.999) 39 gl_FragColor = vec4(1.0); 40 else 41 gl_FragColor = vec4(0.4, t.y, val, 1.0); 42 } 43 else if (t.y > c0.x  0.03) 44 { 45 /* Grass */ 46 if (f > 0.99) 47 gl_FragColor = vec4(0.4, 0.7, 0.3, 1.0); 48 else if (f > 0.9) 49 gl_FragColor = vec4(0.3, 0.6, 0.2, 1.0); 50 else 51 gl_FragColor = vec4(0.2, 0.5, 0.1, 1.0); 52 } 53 else 54 { 55 /* Earth */ 56 if (f > 0.99) 57 gl_FragColor = vec4(0.7, 0.4, 0.3, 1.0); 58 else if (f > 0.9) 59 gl_FragColor = vec4(0.6, 0.3, 0.2, 1.0); 60 else 61 gl_FragColor = vec4(0.5, 0.2, 0.1, 1.0); 62 } 55 float c0 = texture2D(u_Texture, tc0).x; 56 float c1 = texture2D(u_Texture, tc1).x; 57 float c2 = texture2D(u_Texture, tc2).x; 58 float c3 = texture2D(u_Texture, tc3).x; 59 60 /* Artificially compress in Y */ 61 c0 *= 0.3; 62 c1 *= 0.3; 63 c2 *= 0.3; 64 c3 *= 0.3; 65 66 vec2 p0 = vec2(tc0.x * width, c0 * height); 67 vec2 p1 = vec2(tc1.x * width, c1 * height); 68 vec2 p2 = vec2(tc2.x * width, c2 * height); 69 vec2 p3 = vec2(tc3.x * width, c3 * height); 70 vec2 a = vec2(t.x * width, t.y * height); 71 72 float d0 = point2segment(p0, p1, a); 73 float d1 = point2segment(p1, p2, a); 74 float d2 = point2segment(p2, p3, a); 75 76 float d = clamp(line_width  min(min(d0, d1), d2), 0.0, 1.0); 77 78 gl_FragColor = vec4(t.y, d, d * 0.3, 1.0); 63 79 } 64 80
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