62 lines
1.5 KiB
HLSL
62 lines
1.5 KiB
HLSL
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// --------------------------------
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// common lighting operations
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// --------------------------------
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float3 lRenderSun(float3 ray_dir, float3 sun_dir, float3 sun_col = float3(0.8, 0.4, 0.1)) {
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float alignment = min(acos(dot(ray_dir, sun_dir)), 1);
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float sun_amount = pow(0.025/alignment, 3);
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return sun_amount * sun_col;
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}
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// a basic procedural sky
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float3 lRenderSky(float3 ray_dir, float3 sun_dir) {
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float3 rendered_sun = lRenderSun(ray_dir, sun_dir);
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float a = 1 - abs(ray_dir.y);
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return lerp(float3(0.3, 0.3, 0.7), float3(0.6, 0.7, 0.9), a) + rendered_sun;
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}
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//calculate sky light
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float3 lSky(float3 normal, float3 sky_col = float3(0.1, 0.16, 0.18)) {
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return sky_col * (0.5 + 0.5 * normal.y);
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}
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float lSun(float3 normal, float3 sun_dir, float3 sun_col = float3(1, 0.78, 0.43)) {
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return sun_col * max(dot(normal, sun_dir), 0);
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}
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// soft shadows
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float lShadow(float3 p, float3 sun_dir, float sharpness = 8) {
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float shadow = 1;
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for (float ray_len = 0.001; ray_len < MAX_DIST / 2.0;)
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{
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float dist = DISTANCE_FN(p + sun_dir * ray_len);
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if (dist < SURF_DIST) return 0;
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shadow = min(shadow, sharpness * dist / ray_len);
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ray_len += dist;
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}
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return shadow;
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}
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// --------------------------------
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// misc
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// --------------------------------
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float3 HSV(float h, float s, float v) {
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h *= 6;
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float c = s * v;
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float x = c * (1 - abs(fmod(h, 2) - 1));
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float m = v - c;
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c += m;
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x += m;
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float3 colors[6] = {
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float3(c, x, m),
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float3(x, c, m),
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float3(m, c, x),
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float3(m, x, c),
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float3(x, m, c),
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float3(c, m, x)};
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return colors[int(h)];
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}
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