void DrawRequest::SetDrawElementsCount(GLsizei drawElementsCount)
{
GLint lastDrawIndex = GetStartDrawIndex() + drawElementsCount - 1;
if (lastDrawIndex < GetVerticesCount())
{
m_drawElementsCount = drawElementsCount;
}
else
{
Log("WARNING: Last draw index exeeds available bounds. Truncated drawing elements count");
m_drawElementsCount = GetVerticesCount() - GetStartDrawIndex();
}
}
void DrawRequest::SetStartDrawIndex(GLint startDrawIndex)
{
if (startDrawIndex < GetVerticesCount())
{
m_startDrawIndex = startDrawIndex;
int lastDrawIndex = startDrawIndex + GetDrawElementsCount() - 1;
if (lastDrawIndex >= GetVerticesCount())
{
Log("WARNING: Last draw index exeeds available bounds. Truncated drawing elements count");
int drawElementsCount = GetVerticesCount() - startDrawIndex;
SetDrawElementsCount(drawElementsCount);
}
}
else
{
Log("ERROR: Wrong start draw index");
m_startDrawIndex = 0;
SetDrawElementsCount(0);
}
}
void Mesh::RecalcTangents()
{
if (!HasNormals() || !HasTexCoords()) return;
Vector3f *verts = (Vector3f *)vertices->Map(GL_READ_ONLY);
Vector2f *texs = (Vector2f *)texCoords->Map(GL_READ_ONLY);
int *inds = (int *)indices->Map(GL_READ_ONLY);
int verticesCount = GetVerticesCount();
int indicesCount = GetIndicesCount();
Vector3f *ts = new Vector3f[verticesCount];
Vector3f *bs = new Vector3f[verticesCount];
for (int i = 0; i < indicesCount; i += 3)
{
int i1 = inds[i], i2 = inds[i+1], i3 = inds[i+2];
Vector3f &v1 = verts[i1];
Vector3f &v2 = verts[i2];
Vector3f &v3 = verts[i3];
Vector2f &t1 = texs[i1];
Vector2f &t2 = texs[i2];
Vector2f &t3 = texs[i3];
Vector3f edge1 = v2 - v1;
Vector3f edge2 = v3 - v1;
Vector2f uv1 = t2 - t1;
Vector2f uv2 = t3 - t1;
float f = 1.0f / (uv1.x * uv2.y - uv2.x * uv1.y);
Vector3f tangent = (uv2.y * edge1 - uv1.y * edge2) * f;
Vector3f binormal = (uv1.x * edge2 - uv2.x * edge1) * f;
tangent.Normalize();
binormal.Normalize();
ts[i1] = ts[i2] = ts[i3] = tangent;
bs[i1] = bs[i2] = bs[i3] = binormal;
}
if (!tangents) tangents = new VertexBuffer(rc, GL_ARRAY_BUFFER);
if (!binormals) binormals = new VertexBuffer(rc, GL_ARRAY_BUFFER);
tangents->SetData(verticesCount*sizeof(Vector3f), ts, GL_STATIC_DRAW);
binormals->SetData(verticesCount*sizeof(Vector3f), bs, GL_STATIC_DRAW);
delete [] ts;
delete [] bs;
vertices->Unmap();
texCoords->Unmap();
indices->Unmap();
}
void DrawRequest::ResetDrawCount()
{
GLsizei drawCount = GetVerticesCount() - GetStartDrawIndex();
SetDrawElementsCount(drawCount);
}
