From 44a4e7f9dc728f01d952190e8ca8626125dc30ed Mon Sep 17 00:00:00 2001
From: Reese Gallagher <satchelfrost@gmail.com>
Date: Wed, 31 Jul 2024 22:32:48 -0400
Subject: [PATCH] Added example to demonstrate drawing a model as a point cloud

---
 examples/models/models_point_rendering.c | 72 ++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 examples/models/models_point_rendering.c

diff --git a/examples/models/models_point_rendering.c b/examples/models/models_point_rendering.c
new file mode 100644
index 000000000..7fc4b6a19
--- /dev/null
+++ b/examples/models/models_point_rendering.c
@@ -0,0 +1,72 @@
+#include "raylib.h"
+#include <stdlib.h>
+#include <math.h>
+
+#define NUM_POINTS 1000
+
+float randFloat()
+{
+    return (float)rand() / RAND_MAX;
+}
+
+static Mesh GenMeshCustom(void)
+{
+    Mesh mesh = { 
+        .triangleCount = 1,
+        .vertexCount = NUM_POINTS,
+        .vertices = (float *)MemAlloc(NUM_POINTS * 3 * sizeof(float)),
+    };
+
+    // https://en.wikipedia.org/wiki/Spherical_coordinate_system
+    for (int i = 0; i < NUM_POINTS; i++) {
+        float theta = PI * randFloat();
+        float phi   = 2 * PI * randFloat();
+        float r     = randFloat();
+        mesh.vertices[i * 3 + 0] = r * sin(theta) * cos(phi);
+        mesh.vertices[i * 3 + 1] = r * sin(theta) * sin(phi);
+        mesh.vertices[i * 3 + 2] = r * cos(theta);
+    }
+
+    // Upload mesh data from CPU (RAM) to GPU (VRAM) memory
+    UploadMesh(&mesh, false);
+    return mesh;
+}
+
+int main()
+{
+    Camera camera = {
+        .position   = {3.0f, 3.0f, 3.0f},
+        .target     = {0.0f, 0.0f, 0.0f},
+        .up         = {0.0f, 1.0f, 0.0f},
+        .fovy       = 45.0f,
+        .projection = CAMERA_PERSPECTIVE,
+    };
+
+    InitWindow(800, 600, "Point Rendering");
+
+    Mesh mesh = GenMeshCustom();
+    Model model = LoadModelFromMesh(mesh);
+    Vector3 position = {0.0f, 0.0f, 0.0f};
+    bool drawSphere = true;
+
+    SetTargetFPS(60);
+
+    while(!WindowShouldClose()) {
+        UpdateCamera(&camera, CAMERA_ORBITAL);
+
+        if (IsKeyPressed(KEY_SPACE)) drawSphere = !drawSphere;
+
+        BeginDrawing();
+            ClearBackground(BLACK);
+            BeginMode3D(camera);
+                DrawModelPoints(model, position, 1.0f, WHITE);
+                if (drawSphere)
+                    DrawSphereWires(position, 1.0f, 10, 10, WHITE);
+            EndMode3D();
+        EndDrawing();
+    }
+
+    UnloadModel(model);
+    CloseWindow();
+    return 0;
+}