59 lines
1.6 KiB
HLSL
59 lines
1.6 KiB
HLSL
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#ifndef POI_MATH
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#define POI_MATH
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#ifndef pi
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#define pi float(3.14159265359)
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#endif
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float4 quaternion_conjugate(float4 v)
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{
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return float4(
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v.x, -v.yzw
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);
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}
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float4 quaternion_mul(float4 v1, float4 v2)
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{
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float4 result1 = (v1.x * v2 + v1 * v2.x);
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float4 result2 = float4(
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- dot(v1.yzw, v2.yzw),
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cross(v1.yzw, v2.yzw)
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);
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return float4(result1 + result2);
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}
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float4 get_quaternion_from_angle(float3 axis, float angle)
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{
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return float4(
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cos(angle / 2.0),
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normalize(axis) * sin(angle / 2.0)
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);
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}
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float4 quaternion_from_vector(float3 inVec)
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{
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return float4(0.0, inVec);
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}
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float degree_to_radius(float degree)
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{
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return(
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degree / 180.0 * pi
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);
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}
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float3 rotate_with_quaternion(float3 inVec, float3 rotation)
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{
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float4 qx = get_quaternion_from_angle(float3(1, 0, 0), degree_to_radius(rotation.x));
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float4 qy = get_quaternion_from_angle(float3(0, 1, 0), degree_to_radius(rotation.y));
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float4 qz = get_quaternion_from_angle(float3(0, 0, 1), degree_to_radius(rotation.z));
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#define MUL3(A, B, C) quaternion_mul(quaternion_mul((A), (B)), (C))
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float4 quaternion = normalize(MUL3(qx, qy, qz));
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float4 conjugate = quaternion_conjugate(quaternion);
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float4 inVecQ = quaternion_from_vector(inVec);
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float3 rotated = (
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MUL3(quaternion, inVecQ, conjugate)
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).yzw;
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return rotated;
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}
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float4 transform(float4 input, float4 pos, float4 rotation, float4 scale)
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{
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input.rgb *= (scale.xyz * scale.w);
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input = float4(rotate_with_quaternion(input.xyz, rotation.xyz/* * rotation.w*/) + (pos.xyz/* * pos.w*/), input.w);
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return input;
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}
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#endif
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