mat4* lookAt(mat4* pOut, const vec3* pEye, const vec3* pCenter,
const vec3* pUp) {
vec3 f;
avec3_subtract(&f, pCenter, pEye);
vec3Normalize(&f, &f);
vec3 s;
vec3Cross(&s, &f, pUp);
vec3Normalize(&s, &s);
vec3 u;
vec3Cross(&u, &s, &f);
pOut->mat[0] = s.x;
pOut->mat[1] = u.x;
pOut->mat[2] = -f.x;
pOut->mat[3] = 0.0;
pOut->mat[4] = s.y;
pOut->mat[5] = u.y;
pOut->mat[6] = -f.y;
pOut->mat[7] = 0.0;
pOut->mat[8] = s.z;
pOut->mat[9] = u.z;
pOut->mat[10] = -f.z;
pOut->mat[11] = 0.0;
pOut->mat[12] = -vec3Dot(&s, pEye);
pOut->mat[13] = -vec3Dot(&u, pEye);
pOut->mat[14] = vec3Dot(&f, pEye);
pOut->mat[15] = 1.0;
return pOut;
}
// Inverse edge length weighted method. As described in Real-time rendering (3rd ed.) p.546.
// Ref: Max, N. L., (1999) 'Weights for computing vertex normals from facet normals'
// in Journal of grahics tools, vol.4, no.2, pp.1-6.
static GLfloat* meshGenerateNormals(int num_verts, int num_elems, const GLfloat *verts, const GLushort *elems)
{
GLfloat *norms = (GLfloat*) calloc(3*num_verts, sizeof(GLfloat));
GLfloat e1[3], e2[3], no[3];
for (int i = 0; i < num_elems; i += 3) {
for (int j = 0; j < 3; ++j) {
int a = 3*elems[i+j];
int b = 3*elems[i+((j+1)%3)];
int c = 3*elems[i+((j+2)%3)];
vec3Sub(e1, &verts[c], &verts[b]);
vec3Sub(e2, &verts[a], &verts[b]);
vec3Cross(no, e1, e2);
double d = vec3Length2(e1) * vec3Length2(e2);
vec3DivScalar(no, no, d);
vec3Add(&norms[b], &norms[b], no);
}
}
for (int i = 0; i < 3*num_verts; i += 3) {
vec3Normalize(&norms[i], &norms[i]);
}
return norms;
}
//===========================================================================
int Scene::addPolygon(int* inVerts)
{
manta_assert(polyCount < MAX_SCENE_POLYS, "Error, attempting to add too many Polygons!\n");
color3f white;
vec3Set(&white, 1.f, 1.f, 1.f);
vec3 edgeA, edgeB, normal;
vec3* verts[3];
verts[0] = &sceneVertices[inVerts[0]];
verts[1] = &sceneVertices[inVerts[1]];
verts[2] = &sceneVertices[inVerts[2]];
vec3Sub(&edgeA, verts[0], verts[1]);
vec3Sub(&edgeB, verts[0], verts[2]);
vec3Cross(&normal, &edgeB, &edgeA);
vec3Unit(&normal);
scenePolygons[polyCount].pointIndex[0] = inVerts[0];
scenePolygons[polyCount].pointIndex[1] = inVerts[1];
scenePolygons[polyCount].pointIndex[2] = inVerts[2];
debugBuildPoly(&scenePolygons[polyCount++],
verts[0],
verts[1],
verts[2],
&normal,
&white);
return polyCount-1;
}
void invRotMatrixFromVec3(matrix* out, vec3* dir, vec3* up)
{
vec3 right;
vec3Cross(&right, dir, up);
vec3Cpy((vec3*)&out->row[0], &right);
vec3Cpy((vec3*)&out->row[1], up);
vec3Cpy((vec3*)&out->row[2], dir);
}
Matrix4 mat4LookAt(const Vector3 &eye, const Vector3 ¢er, const Vector3 &up)
{
// Forward vector
Vector3 f = eye - center;
f.normalize();
// Right vector
Vector3 r = vec3Cross(up, f);
r.normalize();
// Up vector
Vector3 u = vec3Cross(f, r);
u.normalize();
// Create matrix
Matrix4 mat(r.x, r.y, r.z, 0.0f,
u.x, u.y, u.z, 0.0f,
f.x, f.y, f.z, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f );
return mat * mat4Translation(-eye);
}
void mtxLookAtImpl(float* _result, const float* _eye, const float* _view, const float* _up)
{
float up[3] = { 0.0f, 1.0f, 0.0f };
if (NULL != _up)
{
up[0] = _up[0];
up[1] = _up[1];
up[2] = _up[2];
}
float tmp[4];
vec3Cross(tmp, up, _view);
float right[4];
vec3Norm(right, tmp);
vec3Cross(up, _view, right);
memSet(_result, 0, sizeof(float)*16);
_result[ 0] = right[0];
_result[ 1] = up[0];
_result[ 2] = _view[0];
_result[ 4] = right[1];
_result[ 5] = up[1];
_result[ 6] = _view[1];
_result[ 8] = right[2];
_result[ 9] = up[2];
_result[10] = _view[2];
_result[12] = -vec3Dot(right, _eye);
_result[13] = -vec3Dot(up, _eye);
_result[14] = -vec3Dot(_view, _eye);
_result[15] = 1.0f;
}
void rotMatrixFromVec3(matrix* out, vec3* dir, vec3* up)
{
vec3 right;
vec3Cross(&right, dir, up);
out->row[0].x = right.x;
out->row[1].x = right.y;
out->row[2].x = right.z;
out->row[0].y = up->x;
out->row[1].y = up->y;
out->row[2].y = up->z;
out->row[0].z = dir->x;
out->row[1].z = dir->y;
out->row[2].z = dir->z;
}
void calcTangents(void* _vertices, uint16_t _numVertices, bgfx::VertexDecl _decl, const uint16_t* _indices, uint32_t _numIndices)
{
struct PosTexcoord
{
float m_x;
float m_y;
float m_z;
float m_pad0;
float m_u;
float m_v;
float m_pad1;
float m_pad2;
};
float* tangents = new float[6*_numVertices];
memset(tangents, 0, 6*_numVertices*sizeof(float) );
PosTexcoord v0;
PosTexcoord v1;
PosTexcoord v2;
for (uint32_t ii = 0, num = _numIndices/3; ii < num; ++ii)
{
const uint16_t* indices = &_indices[ii*3];
uint32_t i0 = indices[0];
uint32_t i1 = indices[1];
uint32_t i2 = indices[2];
bgfx::vertexUnpack(&v0.m_x, bgfx::Attrib::Position, _decl, _vertices, i0);
bgfx::vertexUnpack(&v0.m_u, bgfx::Attrib::TexCoord0, _decl, _vertices, i0);
bgfx::vertexUnpack(&v1.m_x, bgfx::Attrib::Position, _decl, _vertices, i1);
bgfx::vertexUnpack(&v1.m_u, bgfx::Attrib::TexCoord0, _decl, _vertices, i1);
bgfx::vertexUnpack(&v2.m_x, bgfx::Attrib::Position, _decl, _vertices, i2);
bgfx::vertexUnpack(&v2.m_u, bgfx::Attrib::TexCoord0, _decl, _vertices, i2);
const float bax = v1.m_x - v0.m_x;
const float bay = v1.m_y - v0.m_y;
const float baz = v1.m_z - v0.m_z;
const float bau = v1.m_u - v0.m_u;
const float bav = v1.m_v - v0.m_v;
const float cax = v2.m_x - v0.m_x;
const float cay = v2.m_y - v0.m_y;
const float caz = v2.m_z - v0.m_z;
const float cau = v2.m_u - v0.m_u;
const float cav = v2.m_v - v0.m_v;
const float det = (bau * cav - bav * cau);
const float invDet = 1.0f / det;
const float tx = (bax * cav - cax * bav) * invDet;
const float ty = (bay * cav - cay * bav) * invDet;
const float tz = (baz * cav - caz * bav) * invDet;
const float bx = (cax * bau - bax * cau) * invDet;
const float by = (cay * bau - bay * cau) * invDet;
const float bz = (caz * bau - baz * cau) * invDet;
for (uint32_t jj = 0; jj < 3; ++jj)
{
float* tanu = &tangents[indices[jj]*6];
float* tanv = &tanu[3];
tanu[0] += tx;
tanu[1] += ty;
tanu[2] += tz;
tanv[0] += bx;
tanv[1] += by;
tanv[2] += bz;
}
}
for (uint32_t ii = 0; ii < _numVertices; ++ii)
{
const float* tanu = &tangents[ii*6];
const float* tanv = &tangents[ii*6 + 3];
float normal[4];
bgfx::vertexUnpack(normal, bgfx::Attrib::Normal, _decl, _vertices, ii);
float ndt = vec3Dot(normal, tanu);
float nxt[3];
vec3Cross(nxt, normal, tanu);
float tmp[3];
tmp[0] = tanu[0] - normal[0] * ndt;
tmp[1] = tanu[1] - normal[1] * ndt;
tmp[2] = tanu[2] - normal[2] * ndt;
float tangent[4];
vec3Norm(tangent, tmp);
tangent[3] = vec3Dot(nxt, tanv) < 0.0f ? -1.0f : 1.0f;
bgfx::vertexPack(tangent, true, bgfx::Attrib::Tangent, _decl, _vertices, ii);
}
delete [] tangents;
}
void update(float _deltaTime)
{
if (m_mouseDown)
{
int32_t deltaX = m_mouseNow.m_mx - m_mouseLast.m_mx;
int32_t deltaY = m_mouseNow.m_my - m_mouseLast.m_my;
m_horizontalAngle += m_mouseSpeed * float(deltaX);
m_verticalAngle -= m_mouseSpeed * float(deltaY);
m_mouseLast.m_mx = m_mouseNow.m_mx;
m_mouseLast.m_my = m_mouseNow.m_my;
}
float direction[3] =
{
cosf(m_verticalAngle) * sinf(m_horizontalAngle),
sinf(m_verticalAngle),
cosf(m_verticalAngle) * cosf(m_horizontalAngle),
};
float right[3] =
{
sinf(m_horizontalAngle - float(M_PI)/2.0f),
0,
cosf(m_horizontalAngle - float(M_PI)/2.0f),
};
if (m_keys & CAMERA_KEY_UP)
{
// m_eye += direction * _deltaTime * m_moveSpeed
float tmpRhs[3];
float tmpPos[3];
memcpy(tmpPos, m_eye, sizeof(float)*3);
vec3Mul(tmpRhs, direction, _deltaTime * m_moveSpeed);
vec3Add(m_eye, tmpPos, tmpRhs);
setKeyState(CAMERA_KEY_UP, false);
}
if (m_keys & CAMERA_KEY_DOWN)
{
// m_eye -= direction * _deltaTime * m_moveSpeed
float tmpRhs[3];
float tmpPos[3];
memcpy(tmpPos, m_eye, sizeof(float)*3);
vec3Mul(tmpRhs, direction, _deltaTime * m_moveSpeed);
vec3Sub(m_eye, tmpPos, tmpRhs);
setKeyState(CAMERA_KEY_DOWN, false);
}
if (m_keys & CAMERA_KEY_LEFT)
{
// m_eye += right * _deltaTime * m_moveSpeed
float tmpRhs[3];
float tmpPos[3];
memcpy(tmpPos, m_eye, sizeof(float)*3);
vec3Mul(tmpRhs, right, _deltaTime * m_moveSpeed);
vec3Add(m_eye, tmpPos, tmpRhs);
setKeyState(CAMERA_KEY_LEFT, false);
}
if (m_keys & CAMERA_KEY_RIGHT)
{
// m_eye -= right * _deltaTime * m_moveSpeed
float tmpRhs[3];
float tmpPos[3];
memcpy(tmpPos, m_eye, sizeof(float)*3);
vec3Mul(tmpRhs, right, _deltaTime * m_moveSpeed);
vec3Sub(m_eye, tmpPos, tmpRhs);
setKeyState(CAMERA_KEY_RIGHT, false);
}
vec3Add(m_at, m_eye, direction);
vec3Cross(m_up, right, direction);
}