67 lines
2.3 KiB
GLSL
67 lines
2.3 KiB
GLSL
#version 100
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#extension GL_OES_standard_derivatives : enable
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precision highp float;
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#define INTENSITY_CORRECTION 0.6
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// normalized values for (-0.6/1.31, 0.6/1.31, 1./1.31)
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const vec3 LIGHT_TOP_DIR = vec3(-0.4574957, 0.4574957, 0.7624929);
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#define LIGHT_TOP_DIFFUSE (0.8 * INTENSITY_CORRECTION)
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#define LIGHT_TOP_SPECULAR (0.125 * INTENSITY_CORRECTION)
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#define LIGHT_TOP_SHININESS 20.0
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// normalized values for (1./1.43, 0.2/1.43, 1./1.43)
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const vec3 LIGHT_FRONT_DIR = vec3(0.6985074, 0.1397015, 0.6985074);
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#define LIGHT_FRONT_DIFFUSE (0.3 * INTENSITY_CORRECTION)
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#define INTENSITY_AMBIENT 0.3
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const vec3 ZERO = vec3(0.0, 0.0, 0.0);
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const float EPSILON = 0.0001;
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uniform vec4 uniform_color;
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uniform bool volume_mirrored;
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uniform mat4 view_model_matrix;
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uniform mat3 view_normal_matrix;
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varying vec3 clipping_planes_dots;
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varying vec4 model_pos;
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void main()
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{
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if (any(lessThan(clipping_planes_dots, ZERO)))
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discard;
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vec3 color = uniform_color.rgb;
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float alpha = uniform_color.a;
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vec3 triangle_normal = normalize(cross(dFdx(model_pos.xyz), dFdy(model_pos.xyz)));
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#ifdef FLIP_TRIANGLE_NORMALS
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triangle_normal = -triangle_normal;
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#endif
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if (volume_mirrored)
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triangle_normal = -triangle_normal;
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// First transform the normal into camera space and normalize the result.
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vec3 eye_normal = normalize(view_normal_matrix * triangle_normal);
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// Compute the cos of the angle between the normal and lights direction. The light is directional so the direction is constant for every vertex.
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// Since these two are normalized the cosine is the dot product. We also need to clamp the result to the [0,1] range.
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float NdotL = max(dot(eye_normal, LIGHT_TOP_DIR), 0.0);
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// x = diffuse, y = specular;
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vec2 intensity = vec2(0.0);
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intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
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vec3 position = (view_model_matrix * model_pos).xyz;
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intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(position), reflect(-LIGHT_TOP_DIR, eye_normal)), 0.0), LIGHT_TOP_SHININESS);
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// Perform the same lighting calculation for the 2nd light source (no specular applied).
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NdotL = max(dot(eye_normal, LIGHT_FRONT_DIR), 0.0);
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intensity.x += NdotL * LIGHT_FRONT_DIFFUSE;
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gl_FragColor = vec4(vec3(intensity.y) + color * intensity.x, alpha);
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}
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