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Code Issues 7 Releases Wiki Activity

LinesOfSight: support multiple NPCs

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This commit is contained in:
Colin McMillen 2020-03-09 14:47:21 -04:00
parent 473256d105
commit 9504c2236c
1 changed files with 35 additions and 14 deletions
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37
Shared/LinesOfSight.cs
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@ -5,18 +5,27 @@ using System;
namespace SemiColinGames {
public sealed class LinesOfSight : IDisposable {
const int NUM_EDGE_VERTICES = 60;
// Max number of NPCs whose vision cones will be shown at once.
const int MAX_NPCS = 4;
// Number of edge vertices per vision cone.
const int NUM_EDGE_VERTICES = 30;
readonly VertexBuffer vertexBuffer;
readonly IndexBuffer indexBuffer;
// coneVertices[0] is the eye position; the rest are the edge vertices.
readonly VertexPositionColor[] coneVertices = new VertexPositionColor[NUM_EDGE_VERTICES + 1];
readonly bool[] coneEnabled = new bool[MAX_NPCS];
// coneVertices[i][0] is the eye position; the rest are the edge vertices.
readonly VertexPositionColor[][] coneVertices = new VertexPositionColor[MAX_NPCS][];
// The number of total triangles drawn is one less than the number of edge points.
readonly int[] indices = new int[(NUM_EDGE_VERTICES - 1) * 3];
Color color = Color.FromNonPremultiplied(new Vector4(0, 0, 1, 0.6f));
public LinesOfSight(GraphicsDevice graphics) {
for (int i = 0; i < MAX_NPCS; i++) {
coneVertices[i] = new VertexPositionColor[NUM_EDGE_VERTICES + 1];
}
vertexBuffer = new VertexBuffer(
graphics, typeof(VertexPositionColor), NUM_EDGE_VERTICES * 3, BufferUsage.WriteOnly);
indexBuffer = new IndexBuffer(
@ -34,8 +43,16 @@ namespace SemiColinGames {
}
public void Update(NPC[] npcs, AABB[] collisionTargets) {
NPC npc = npcs[0];
for (int i = 0; i < MAX_NPCS; i++) {
coneEnabled[i] = false;
}
for (int i = 0; i < MAX_NPCS; i++) {
UpdateNpc(i, npcs[i], collisionTargets);
}
}
private void UpdateNpc(int index, NPC npc, AABB[] collisionTargets) {
coneEnabled[index] = true;
Vector2 eyePos = npc.EyePosition;
float visionRange = npc.VisionRange;
Vector2 ray = npc.VisionRay;
@ -44,7 +61,7 @@ namespace SemiColinGames {
float visionRangeSq = visionRange * visionRange;
float fovStep = fov / (NUM_EDGE_VERTICES - 1);
coneVertices[0] = new VertexPositionColor(new Vector3(npc.EyePosition, 0), color);
coneVertices[index][0] = new VertexPositionColor(new Vector3(npc.EyePosition, 0), color);
for (int i = 0; i < NUM_EDGE_VERTICES; i++) {
float angle = -fov / 2 + fovStep * i;
Vector2 rotated = ray.Rotate(angle);
@ -73,19 +90,22 @@ namespace SemiColinGames {
float tint = 0.6f - hitTime / 2;
Color tinted = Color.FromNonPremultiplied(new Vector4(0, 0, 1, tint));
coneVertices[i + 1] = new VertexPositionColor(new Vector3(closestHit, 0), tinted);
coneVertices[index][i + 1] = new VertexPositionColor(new Vector3(closestHit, 0), tinted);
}
}
public void Draw(GraphicsDevice graphics, BasicEffect lightingEffect) {
for (int i = 0; i < NUM_EDGE_VERTICES - 1; i++) {
indices[i * 3] = 0;
indices[i * 3 + 1] = i + 1;
indices[i * 3 + 2] = i + 2;
}
vertexBuffer.SetData(coneVertices);
for (int npcIndex = 0; npcIndex < MAX_NPCS; npcIndex++) {
if (!coneEnabled[npcIndex]) {
continue;
}
vertexBuffer.SetData(coneVertices[npcIndex]);
indexBuffer.SetData(indices);
graphics.SetVertexBuffer(vertexBuffer);
graphics.Indices = indexBuffer;
@ -97,3 +117,4 @@ namespace SemiColinGames {
}
}
}
}