/// <summary>Checks if a block specified by its bounding rectangle intersects any of the specified triangles.</summary>
/// <param name="block">The bounding rectangle of the block.</param>
/// <param name="triangles">An array of triangles that was obtained from a call to InitializeBlockClipping.</param>
/// <returns>Whether the block intersects any of the triangles.</returns>
private static bool BlockIntersectsTriangles(ObjectGrid.GridBounds block, Triangle[] triangles)
{
for (int i = 0; i < triangles.Length; i++) {
if (BlockIntersectsTriangle(block, triangles[i])) {
return true;
}
}
return false;
}
/// <summary>Renders the objects attached to a specified populated leaf node.</summary>
/// <param name="leaf">The leaf node to render.</param>
private static void RenderGridLeafNode(ObjectGrid.GridPopulatedLeafNode leaf, bool includeVisibleLeafNodes)
{
/* Create the display list for the leaf node if not yet available. */
if (leaf.DisplayList.IsUnavailable()) {
leaf.CreateOrUpdateDisplayList();
}
/* Render the leaf node if the display list is available. */
if (leaf.DisplayList.IsAvailable()) {
double x = 0.5 * (leaf.Rectangle.Left + leaf.Rectangle.Right) - Camera.GridLeafNodeCenter.X;
double y = -Camera.GridLeafNodeCenter.Y;
double z = 0.5 * (leaf.Rectangle.Near + leaf.Rectangle.Far) - Camera.GridLeafNodeCenter.Z;
Gl.glPushMatrix();
Gl.glTranslated(x, y, z);
leaf.DisplayList.Call();
Gl.glPopMatrix();
}
}
/// <summary>Checks if a block specified by its bounding rectangle intersects a specified triangle.</summary>
/// <param name="block">The bounding rectangle of the block.</param>
/// <param name="triangles">The triangle.</param>
/// <returns>Whether the block intersects the triangle.</returns>
private static bool BlockIntersectsTriangle(ObjectGrid.GridBounds block, Triangle triangle)
{
/*
* First, let's check if the bounding rectangle of the
* block intersects the bounding rectangle of the
* triangle. If so, we need further checks to ensure
* that the actual triangle intersects the block,
* but if not, the triangle cannot intersect the block.
* */
if (
block.Left <= triangle.BoundingRectangle.Right &
block.Right >= triangle.BoundingRectangle.Left &
block.Near <= triangle.BoundingRectangle.Far &
block.Far >= triangle.BoundingRectangle.Near
) {
/*
* The bounding rectangles intersect. This means that
* the triangle could intersect the block, but not
* necessarily. First, let's check if any point of
* the triangle lies inside the rectangle.
* */
if (
triangle.PointA.X >= block.Left && triangle.PointA.X <= block.Right &&
triangle.PointA.Y >= block.Near && triangle.PointA.Y <= block.Far
) {
return true;
} else if (
triangle.PointB.X >= block.Left && triangle.PointB.X <= block.Right &&
triangle.PointB.Y >= block.Near && triangle.PointB.Y <= block.Far
) {
return true;
} else if (
triangle.PointC.X >= block.Left && triangle.PointC.X <= block.Right &&
triangle.PointC.Y >= block.Near && triangle.PointC.Y <= block.Far
) {
return true;
} else {
/*
* There is no point of the triangle that lies inside
* the rectangle. Now, let's check if any point of the
* rectangle lies inside the triangle.
* */
if (IsPointInTriangle(new OpenBveApi.Math.Vector2(block.Left, block.Near), triangle)) {
return true;
} else if (IsPointInTriangle(new OpenBveApi.Math.Vector2(block.Left, block.Far), triangle)) {
return true;
} else if (IsPointInTriangle(new OpenBveApi.Math.Vector2(block.Right, block.Far), triangle)) {
return true;
} else if (IsPointInTriangle(new OpenBveApi.Math.Vector2(block.Right, block.Near), triangle)) {
return true;
} else {
/* No point of the rectangle lies inside the triangle.
* Now, let's check each edge of the triangle against
* each edge of the rectangle for intersection.
* */
for (int i = 0; i < 3; i++) {
OpenBveApi.Math.Vector2 a;
OpenBveApi.Math.Vector2 b;
if (i == 0) {
a = triangle.PointA;
b = triangle.PointB;
} else if (i == 1) {
a = triangle.PointB;
b = triangle.PointC;
} else {
a = triangle.PointC;
b = triangle.PointA;
}
/*
* Compare the current triangle edge against the
* left and right vertical edges of the rectangle.
* */
{
double denominator = a.X - b.X;
if (denominator == 0.0) {
if (a.X >= block.Left & a.X <= block.Right) {
if (a.Y <= block.Near & b.Y >= block.Far | a.Y >= block.Far & b.Y <= block.Near) {
return true;
}
}
} else {
for (int j = 0; j < 2; j++) {
double px = j == 0 ? block.Left : block.Right;
double numerator = a.Y * (px - b.X) - b.Y * (px - a.X);
double py = numerator / denominator;
if (py >= block.Near & py <= block.Far) {
double r = (px - a.X) / (b.X - a.X);
if (r >= 0.0 & r <= 1.0) {
return true;
}
}
}
}
}
/*
* Compare the current triangle edge against the
* near and far horizontal edges of the rectangle.
* */
{
double denominator = a.Y - b.Y;
if (denominator == 0.0) {
if (a.Y >= block.Near & a.Y <= block.Far) {
if (a.X <= block.Left & b.X >= block.Right | a.X >= block.Right & b.X <= block.Left) {
return true;
}
}
} else {
for (int j = 0; j < 2; j++) {
double py = j == 0 ? block.Near : block.Far;
double numerator = a.X * (py - b.Y) - b.X * (py - a.Y);
double px = numerator / denominator;
if (px >= block.Left & px <= block.Right) {
double r = (py - a.Y) / (b.Y - a.Y);
if (r >= 0.0 & r <= 1.0) {
return true;
}
}
}
}
}
}
/*
* No point of the triangle lies inside the rectangle,
* no point of the rectangle lies inside the triangle,
* and no triangle edge intersects with a rectangle
* edge. Thus, the triangle does not intersect the
* rectangle.
* */
return false;
}
}
} else {
/*
* The bounding rectangles do not intersect. The
* triangle itself thus cannot intersect the block.
* */
return false;
}
}
/// <summary>Renders the opaque part of a set of specified static objects.</summary>
/// <param name="objects">The list of static objects.</param>
/// <param name="count">The number of static objects.</param>
/// <param name="count">The current OpenGL state.</param>
/// <remarks>This function may change the texture or emissive color in the current OpenGL state.</remarks>
internal static void RenderStaticOpaqueObjects(ObjectGrid.StaticOpaqueObject[] objects, int count, ref OpenGlState state)
{
/*
* Count the number of faces.
* */
int faceCount = 0;
for (int i = 0; i < count; i++) {
OpenBveApi.Geometry.FaceVertexMesh mesh = ObjectLibrary.Library.Objects[objects[i].LibraryIndex] as OpenBveApi.Geometry.FaceVertexMesh;
if (mesh != null) {
faceCount += mesh.Faces.Length;
}
}
/*
* Sort the faces by shared material properties. This will later increase
* rendering speed as fewer state changes will be involved in OpenGL.
* */
Face[] faces = new Face[faceCount];
long[] keys = new long[faceCount];
faceCount = 0;
for (int i = 0; i < count; i++) {
OpenBveApi.Geometry.FaceVertexMesh mesh = ObjectLibrary.Library.Objects[objects[i].LibraryIndex] as OpenBveApi.Geometry.FaceVertexMesh;
if (mesh != null) {
for (int j = 0; j < mesh.Faces.Length; j++) {
int material = mesh.Faces[j].Material;
long texture =
mesh.Materials[material].DaytimeTexture is Textures.ApiHandle ?
(long)(((Textures.ApiHandle)mesh.Materials[material].DaytimeTexture).TextureIndex) + 1 :
(long)0;
long emissive =
(long)(255.0f * mesh.Materials[material].EmissiveColor.R) |
(long)(255.0f * mesh.Materials[material].EmissiveColor.G) << 8 |
(long)(255.0f * mesh.Materials[material].EmissiveColor.B) << 16;
faces[faceCount] = new Face(i, j);
keys[faceCount] = texture | emissive << 32;
faceCount++;
}
}
}
Array.Sort<long, Face>(keys, faces);
/*
* Render the faces.
* */
state.SetAlphaFunction(Gl.GL_EQUAL, 1.0f);
for (int i = 0; i < faceCount; i++) {
int objectIndex = faces[i].ObjectIndex;
OpenBveApi.Geometry.FaceVertexMesh mesh = ObjectLibrary.Library.Objects[objects[objectIndex].LibraryIndex] as OpenBveApi.Geometry.FaceVertexMesh;
if (mesh != null) {
int material = mesh.Faces[faces[i].FaceIndex].Material;
if (mesh.Materials[material].BlendMode == OpenBveApi.Geometry.BlendMode.Normal) {
RenderFace(mesh, faces[i].FaceIndex, objects[objectIndex].GridPosition, objects[objectIndex].GridOrientation, ref state);
}
}
}
}