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OpenGL2: Reimplement MD3 tangent space calculation.

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This commit is contained in:
SmileTheory 2014-05-27 18:20:12 -07:00
parent 347b429fdb
commit 318d45cff5
4 changed files with 56 additions and 70 deletions
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37
code/renderergl2/tr_main.c
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@ -294,13 +294,11 @@ void R_CalcTangentSpaceFast(vec3_t tangent, vec3_t bitangent, vec3_t normal,
/*
http://www.terathon.com/code/tangent.html
*/
void R_CalcTBN(vec3_t tangent, vec3_t bitangent, vec3_t normal,
const vec3_t v1, const vec3_t v2, const vec3_t v3, const vec2_t w1, const vec2_t w2, const vec2_t w3)
void R_CalcTexDirs(vec3_t sdir, vec3_t tdir, const vec3_t v1, const vec3_t v2,
const vec3_t v3, const vec2_t w1, const vec2_t w2, const vec2_t w3)
{
vec3_t u, v;
float x1, x2, y1, y2, z1, z2;
float s1, s2, t1, t2;
float r, dot;
float s1, s2, t1, t2, r;
x1 = v2[0] - v1[0];
x2 = v3[0] - v1[0];
@ -316,24 +314,27 @@ void R_CalcTBN(vec3_t tangent, vec3_t bitangent, vec3_t normal,
r = 1.0f / (s1 * t2 - s2 * t1);
VectorSet(tangent, (t2 * x1 - t1 * x2) * r, (t2 * y1 - t1 * y2) * r, (t2 * z1 - t1 * z2) * r);
VectorSet(bitangent, (s1 * x2 - s2 * x1) * r, (s1 * y2 - s2 * y1) * r, (s1 * z2 - s2 * z1) * r);
VectorSet(sdir, (t2 * x1 - t1 * x2) * r, (t2 * y1 - t1 * y2) * r, (t2 * z1 - t1 * z2) * r);
VectorSet(tdir, (s1 * x2 - s2 * x1) * r, (s1 * y2 - s2 * y1) * r, (s1 * z2 - s2 * z1) * r);
}
// compute the face normal based on vertex points
VectorSubtract(v3, v1, u);
VectorSubtract(v2, v1, v);
CrossProduct(u, v, normal);
VectorNormalize(normal);
void R_CalcTbnFromNormalAndTexDirs(vec3_t tangent, vec3_t bitangent, vec3_t normal, vec3_t sdir, vec3_t tdir)
{
vec3_t n_cross_t;
vec_t n_dot_t, handedness;
// Gram-Schmidt orthogonalize
//tangent[a] = (t - n * Dot(n, t)).Normalize();
dot = DotProduct(normal, tangent);
VectorMA(tangent, -dot, normal, tangent);
n_dot_t = DotProduct(normal, sdir);
VectorMA(sdir, -n_dot_t, normal, tangent);
VectorNormalize(tangent);
// B=NxT
//CrossProduct(normal, tangent, bitangent);
// Calculate handedness
CrossProduct(normal, sdir, n_cross_t);
handedness = (DotProduct(n_cross_t, tdir) < 0.0f) ? -1.0f : 1.0f;
// Calculate bitangent
CrossProduct(normal, tangent, bitangent);
VectorScale(bitangent, handedness, bitangent);
}
void R_CalcTBN2(vec3_t tangent, vec3_t bitangent, vec3_t normal,