21 lines
796 B
C
21 lines
796 B
C
#include <c3d/maths.h>
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void Mtx_Ortho(C3D_Mtx* mtx, float left, float right, float bottom, float top, float near, float far, bool isLeftHanded)
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{
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Mtx_Zeros(mtx);
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// Standard orthogonal projection matrix, with a fixed depth range of [-1,0] (required by PICA)
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// http://www.wolframalpha.com/input/?i={{1,0,0,0},{0,1,0,0},{0,0,0.5,-0.5},{0,0,0,1}}{{2/(r-l),0,0,(l%2Br)/(l-r)},{0,2/(t-b),0,(b%2Bt)/(b-t)},{0,0,2/(n-f),(n%2Bf)/(n-f)},{0,0,0,1}}
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mtx->r[0].x = 2.0f / (right - left);
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mtx->r[0].w = (left + right) / (left - right);
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mtx->r[1].y = 2.0f / (top - bottom);
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mtx->r[1].w = (bottom + top) / (bottom - top);
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if (isLeftHanded)
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mtx->r[2].z = 1.0f / (far - near);
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else
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mtx->r[2].z = 1.0f / (near - far);
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mtx->r[2].w = 0.5f*(near + far) / (near - far) - 0.5f;
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mtx->r[3].w = 1.0f;
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}
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