50 lines
1.4 KiB
GLSL
50 lines
1.4 KiB
GLSL
#version 450
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/* Copyright (c) 2019-2024, Sascha Willems
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 the "License";
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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layout (location = 0) in vec3 inUVW;
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layout (location = 0) out vec4 outFragColor;
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#define HASHSCALE3 vec3(443.897, 441.423, 437.195)
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#define STARFREQUENCY 0.01
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// Hash function by Dave Hoskins (https://www.shadertoy.com/view/4djSRW)
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float hash33(vec3 p3)
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{
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p3 = fract(p3 * HASHSCALE3);
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p3 += dot(p3, p3.yxz+vec3(19.19));
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return fract((p3.x + p3.y)*p3.z + (p3.x+p3.z)*p3.y + (p3.y+p3.z)*p3.x);
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}
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vec3 starField(vec3 pos)
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{
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vec3 color = vec3(0.0);
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float threshhold = (1.0 - STARFREQUENCY);
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float rnd = hash33(pos);
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if (rnd >= threshhold)
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{
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float starCol = pow((rnd - threshhold) / (1.0 - threshhold), 16.0);
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color += vec3(starCol);
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}
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return color;
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}
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void main()
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{
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outFragColor = vec4(starField(inUVW), 1.0);
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} |