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Vulkan-Samples/shaders/terrain_tessellation/glsl/terrain.frag
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2025-09-04 10:54:47 +08:00

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2.2 KiB
GLSL

#version 450
/* Copyright (c) 2019-2024, Sascha Willems
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 the "License";
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
layout (set = 0, binding = 1) uniform sampler2D samplerHeight;
layout (set = 0, binding = 2) uniform sampler2DArray samplerLayers;
layout (location = 0) in vec3 inNormal;
layout (location = 1) in vec2 inUV;
layout (location = 2) in vec3 inViewVec;
layout (location = 3) in vec3 inLightVec;
layout (location = 4) in vec3 inEyePos;
layout (location = 5) in vec3 inWorldPos;
layout (location = 0) out vec4 outFragColor;
vec3 sampleTerrainLayer()
{
// Define some layer ranges for sampling depending on terrain height
vec2 layers[6];
layers[0] = vec2(-10.0, 10.0);
layers[1] = vec2(5.0, 45.0);
layers[2] = vec2(45.0, 80.0);
layers[3] = vec2(75.0, 100.0);
layers[4] = vec2(95.0, 150.0);
layers[5] = vec2(140.0, 290.0);
vec3 color = vec3(0.0);
// Get height from displacement map
float height = textureLod(samplerHeight, inUV, 0.0).r * 255.0;
for (int i = 0; i < 6; i++)
{
float range = layers[i].y - layers[i].x;
float weight = (range - abs(height - layers[i].y)) / range;
weight = max(0.0, weight);
color += weight * texture(samplerLayers, vec3(inUV * 16.0, i)).rgb;
}
return color;
}
float fog(float density)
{
const float LOG2 = -1.442695;
float dist = gl_FragCoord.z / gl_FragCoord.w * 0.1;
float d = density * dist;
return 1.0 - clamp(exp2(d * d * LOG2), 0.0, 1.0);
}
void main()
{
vec3 N = normalize(inNormal);
vec3 L = normalize(inLightVec);
vec3 ambient = vec3(0.5);
vec3 diffuse = max(dot(N, L), 0.0) * vec3(1.0);
vec4 color = vec4((ambient + diffuse) * sampleTerrainLayer(), 1.0);
const vec4 fogColor = vec4(0.47, 0.5, 0.67, 0.0);
outFragColor = mix(color, fogColor, fog(0.25));
}