static void imapaint_tri_weights(Object *ob,
const float v1[3], const float v2[3], const float v3[3],
const float co[2], float w[3])
{
float pv1[4], pv2[4], pv3[4], h[3], divw;
float model[4][4], proj[4][4], wmat[3][3], invwmat[3][3];
GLint view[4];
/* compute barycentric coordinates */
/* get the needed opengl matrices */
glGetIntegerv(GL_VIEWPORT, view);
glGetFloatv(GL_MODELVIEW_MATRIX, (float *)model);
glGetFloatv(GL_PROJECTION_MATRIX, (float *)proj);
view[0] = view[1] = 0;
/* project the verts */
imapaint_project(ob, model, proj, v1, pv1);
imapaint_project(ob, model, proj, v2, pv2);
imapaint_project(ob, model, proj, v3, pv3);
/* do inverse view mapping, see gluProject man page */
h[0] = (co[0] - view[0]) * 2.0f / view[2] - 1;
h[1] = (co[1] - view[1]) * 2.0f / view[3] - 1;
h[2] = 1.0f;
/* solve for (w1,w2,w3)/perspdiv in:
* h * perspdiv = Project * Model * (w1 * v1 + w2 * v2 + w3 * v3) */
wmat[0][0] = pv1[0]; wmat[1][0] = pv2[0]; wmat[2][0] = pv3[0];
wmat[0][1] = pv1[1]; wmat[1][1] = pv2[1]; wmat[2][1] = pv3[1];
wmat[0][2] = pv1[3]; wmat[1][2] = pv2[3]; wmat[2][2] = pv3[3];
invert_m3_m3(invwmat, wmat);
mul_m3_v3(invwmat, h);
copy_v3_v3(w, h);
/* w is still divided by perspdiv, make it sum to one */
divw = w[0] + w[1] + w[2];
if (divw != 0.0f) {
mul_v3_fl(w, 1.0f / divw);
}
}
static void imapaint_tri_weights(float matrix[4][4], GLint view[4],
const float v1[3], const float v2[3], const float v3[3],
const float co[2], float w[3])
{
float pv1[4], pv2[4], pv3[4], h[3], divw;
float wmat[3][3], invwmat[3][3];
/* compute barycentric coordinates */
/* project the verts */
imapaint_project(matrix, v1, pv1);
imapaint_project(matrix, v2, pv2);
imapaint_project(matrix, v3, pv3);
/* do inverse view mapping, see gluProject man page */
h[0] = (co[0] - view[0]) * 2.0f / view[2] - 1.0f;
h[1] = (co[1] - view[1]) * 2.0f / view[3] - 1.0f;
h[2] = 1.0f;
/* solve for (w1,w2,w3)/perspdiv in:
* h * perspdiv = Project * Model * (w1 * v1 + w2 * v2 + w3 * v3) */
wmat[0][0] = pv1[0]; wmat[1][0] = pv2[0]; wmat[2][0] = pv3[0];
wmat[0][1] = pv1[1]; wmat[1][1] = pv2[1]; wmat[2][1] = pv3[1];
wmat[0][2] = pv1[3]; wmat[1][2] = pv2[3]; wmat[2][2] = pv3[3];
invert_m3_m3(invwmat, wmat);
mul_m3_v3(invwmat, h);
copy_v3_v3(w, h);
/* w is still divided by perspdiv, make it sum to one */
divw = w[0] + w[1] + w[2];
if (divw != 0.0f) {
mul_v3_fl(w, 1.0f / divw);
}
}
