59 lines
1.8 KiB
GLSL
59 lines
1.8 KiB
GLSL
#version 450
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/* Copyright (c) 2023-2024, Mobica Limited
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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 nearPoint;
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layout(location = 1) in vec3 farPoint;
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layout(location = 2) in mat4 view;
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layout(location = 6) in mat4 projection;
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layout(location = 0) out vec4 outColor;
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vec4 grid(vec3 pos) {
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vec2 coord = pos.xz;
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vec2 derivative = fwidth(coord);
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vec2 grid = abs(fract(coord - 0.5) - 0.5) / derivative;
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float line = min(grid.x, grid.y);
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float minimumz = min(derivative.y, 1);
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float minimumx = min(derivative.x, 1);
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vec4 color = vec4(0.5, 0.5, 0.5, 1.0 - min(line, 1.0));
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if(abs(pos.x) < minimumx)
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color.y = 1;
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if(abs(pos.z) < minimumz)
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color.x = 1;
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return color;
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}
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float fadeFactor(vec3 pos) {
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float z = (projection * view * vec4(pos.xyz, 1.0)).z;
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// Empirical values are used to determine when to cut off the grid before moire patterns become visible.
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return z * 6 - 0.5;
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}
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void main() {
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float t = -nearPoint.y / (farPoint.y - nearPoint.y);
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vec3 pos = nearPoint + t * (farPoint - nearPoint);
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// Display only the lower plane
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if(t < 1) {
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vec4 gridColor = grid(pos);
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outColor = vec4(gridColor.xyz, gridColor.w * fadeFactor(pos));
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}
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else
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outColor = vec4(0.0, 0.0, 0.0, 0.0);
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}
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