47 lines
1.3 KiB
GLSL
47 lines
1.3 KiB
GLSL
#version 300 es
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precision highp float;
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uniform sampler2D u_tex;
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uniform sampler2D u_lut;
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uniform float u_opacity;
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in vec2 lonlat;
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out vec4 fragColor;
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const float PI = 3.141592653589793;
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const vec4 bound = vec4(65.24686922, 13.12169419,
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138.85867996, 55.34323806);
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void main() {
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vec2 uv = vec2(
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(lonlat.x - bound.x) / (bound.z - bound.x), // 经度映射到 u
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1.0 - (lonlat.y - bound.y) / (bound.w - bound.y) // 纬度映射到 v
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);
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// 调试：可以取消注释下面的行来可视化坐标
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// fragColor = vec4(uv.x, 0.0, 0.0, 1.0); return; // UV坐标可视化
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// 显示原始经纬度值（归一化到0-1范围用于可视化）
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// fragColor = vec4((lonlat.x - 60.0)/100.0, (lonlat.y + 10.0)/70.0, 0.0, 1.0);
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// return; // 经纬度可视化
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if(any(lessThan(uv, vec2(0.0))) || any(greaterThan(uv, vec2(1.0)))) {
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discard;
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}
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vec4 texColor = texture(u_tex, uv);
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if (texColor.r <= 0.0196 || texColor.r > 0.29411) {
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discard;
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}
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float value = texColor.r * 3.4;
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value = clamp(value, 0.0, 1.0);
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float alpha = smoothstep(0.07, 0.12, value) * 0.9;
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if (alpha <= 0.001) discard;
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vec4 lutColor = texture(u_lut, vec2(value, 0.5));
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fragColor = vec4(lutColor.rgb, alpha * u_opacity);
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} |