void bp_camera_init (camera_t *camera)
{
COPY3 (camera->location, origin);
COPY3 (camera->direction, z);
COPY3 (camera->up, y);
COPY3 (camera->sky, y);
SMUL (camera->right, 4.0/3.0, x);
}
bool CalculatePolygonNormalFlat(float* position, float* buffer, int bufferLength, int elementSize, int polygonVertices)
{
for (int i = 0; i < bufferLength; i += (elementSize * polygonVertices))
{
float v1[3], v2[3], n[3], sum[] = {0.0f, 0.0f, 0.0f};
for (int j = 0; j < polygonVertices - 2; ++j)
{
float *p1 = &position[i],
*p2 = &position[i + (j + 2) * elementSize],
*p3 = &position[i + (j + 1) * elementSize];
MINUS3(p2, p1, v1);
MINUS3(p3, p1, v2);
CROSS3(v1, v2, n);
normalize3(n);
PLUS3(n, sum, sum);
}
for (int j = 0; j < polygonVertices; ++j)
{
COPY3(&buffer[i + j * elementSize], sum);
}
}
return true;
}
bool CalculateGridNormalFlat(float* position, float* buffer, int bufferLength, int elementSize)
{
if (elementSize < 3)
{
return false;
}
for (int i = 0; i < bufferLength; i += 4 * elementSize)
{
float *p1 = &position[i],
*p2 = &position[i + elementSize],
*p3 = &position[i + 2 * elementSize],
*p4 = &position[i + 3 * elementSize];
float v1[3], v2[3], n1[3], n2[3], n1pn2[3];
//v1 = p2-p1
MINUS3(p2, p1, v1);
MINUS3(p4, p1, v2);
//n1 = v1 x v2
CROSS3(v1, v2, n1);
MINUS3(p4, p1, v1);
MINUS3(p3, p1, v2);
CROSS3(v1, v2, n2);
normalize3(n1);
normalize3(n2);
PLUS3(n1, n2, n1pn2);
normalize3(n1pn2);
COPY3(&buffer[i], n1pn2);
COPY3(&buffer[i + elementSize], n1pn2);
COPY3(&buffer[i + 2 * elementSize], n1pn2);
COPY3(&buffer[i + 3 * elementSize], n1pn2);
}
return true;
}
bool CalculateGridNormalSmooth(float* position, float* buffer, int bufferLength, int elementSize, int numX, int numY)
{
if (elementSize < 3)
{
return false;
}
for (int i = 0; i < bufferLength; i += 4 * elementSize)
{
float *p1 = &position[i],
*p2 = &position[i + elementSize],
*p3 = &position[i + 2 * elementSize],
*p4 = &position[i + 3 * elementSize];
float v1[3], v2[3], n1[3], n2[3], n1pn2[3];
//v1 = p2-p1
MINUS3(p2, p1, v1);
MINUS3(p4, p1, v2);
//n1 = v1 x v2
CROSS3(v1, v2, n1);
MINUS3(p4, p1, v1);
MINUS3(p3, p1, v2);
CROSS3(v1, v2, n2);
normalize3(n1);
normalize3(n2);
PLUS3(n1, n2, n1pn2);
normalize3(n1pn2);
COPY3(&buffer[i], n1pn2);
COPY3(&buffer[i + elementSize], n1);
COPY3(&buffer[i + 2 * elementSize], n2);
COPY3(&buffer[i + 3 * elementSize], n1pn2);
}
// average normals in x axis
for (int i = 0; i < numX - 1; ++i)
{
for (int j = 0; j < numY - 2; ++j)
{
float sum[3];
float *p2, *p3, *pj0, *pj1;
p2 = getGridNormal(buffer, numX, numY, elementSize, i, j, 2);
p3 = getGridNormal(buffer, numX, numY, elementSize, i, j, 3);
pj0 = getGridNormal(buffer, numX, numY, elementSize, i, j + 1, 0);
pj1 = getGridNormal(buffer, numX, numY, elementSize, i, j + 1, 1);
PLUS3(pj0, p2, sum);
COPY3(p2, sum);
COPY3(pj0, sum);
PLUS3(pj1, p3, sum);
COPY3(p3, sum);
COPY3(pj1, sum);
}
}
// average normals in y axis
for (int j = 0; j < numY - 1; ++j)
{
for (int i = 0; i < numX - 2; ++i)
{
float sum[3];
float *p1, *p3, *pi0, *pi2;
p1 = getGridNormal(buffer, numX, numY, elementSize, i, j, 1);
p3 = getGridNormal(buffer, numX, numY, elementSize, i, j, 3);
pi0 = getGridNormal(buffer, numX, numY, elementSize, i + 1, j, 0);
pi2 = getGridNormal(buffer, numX, numY, elementSize, i + 1, j, 2);
PLUS3(pi0, p1, sum);
COPY3(p1, sum);
COPY3(pi0, sum);
PLUS3(pi2, p3, sum);
COPY3(p3, sum);
COPY3(pi2, sum);
}
}
return true;
}
