polished the demo a bit

examples/models/models_point_rendering.c

@@ -1,30 +1,38 @@
 #include "raylib.h"
 #include <stdlib.h>
+#include <stdio.h>
 #include <math.h>
 
-#define NUM_POINTS 1000
+#define MAX_POINTS 10000000
+#define MIN_POINTS 1000
 
 float randFloat()
 {
     return (float)rand() / RAND_MAX;
 }
 
-static Mesh GenMeshCustom(void)
+static Mesh GenMeshCustom(int numPoints)
 {
     Mesh mesh = { 
         .triangleCount = 1,
-        .vertexCount = NUM_POINTS,
+        .vertexCount = numPoints,
-        .vertices = (float *)MemAlloc(NUM_POINTS * 3 * sizeof(float)),
+        .vertices = (float *)MemAlloc(numPoints * 3 * sizeof(float)),
+        .colors = (unsigned char*)MemAlloc(numPoints * 4 * sizeof(unsigned char)),
     };
 
     // https://en.wikipedia.org/wiki/Spherical_coordinate_system
-    for (int i = 0; i < NUM_POINTS; i++) {
+    for (int i = 0; i < numPoints; i++) {
         float theta = PI * randFloat();
         float phi   = 2 * PI * randFloat();
-        float r     = randFloat();
+        float r     = 10.0f * 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);
+        Color color = ColorFromHSV(r * 360.0f, 1.0f, 1.0f);
+        mesh.colors[i * 4 + 0] = color.r;
+        mesh.colors[i * 4 + 1] = color.g;
+        mesh.colors[i * 4 + 2] = color.b;
+        mesh.colors[i * 4 + 3] = color.a;
     }
 
     // Upload mesh data from CPU (RAM) to GPU (VRAM) memory
@@ -44,25 +52,81 @@ int main()
 
     InitWindow(800, 600, "Point Rendering");
 
-    Mesh mesh = GenMeshCustom();
-    Model model = LoadModelFromMesh(mesh);
     Vector3 position = {0.0f, 0.0f, 0.0f};
-    bool drawSphere = true;
+    bool newMethod = true;
+    bool numPointsChanged = false;
+    int numPoints = 1000;
+    Mesh mesh = GenMeshCustom(numPoints);
+    Model model = LoadModelFromMesh(mesh);
 
     SetTargetFPS(60);
 
     while(!WindowShouldClose()) {
         UpdateCamera(&camera, CAMERA_ORBITAL);
 
-        if (IsKeyPressed(KEY_SPACE)) drawSphere = !drawSphere;
+        if (IsKeyPressed(KEY_SPACE)) newMethod = !newMethod;
+        if (IsKeyPressed(KEY_UP)) {
+            numPoints = (numPoints * 10 > MAX_POINTS) ? MAX_POINTS : numPoints * 10;
+            numPointsChanged = true;
+            TraceLog(LOG_INFO, "num points %d", numPoints);
+        }
+        if (IsKeyPressed(KEY_DOWN)) {
+            numPoints = (numPoints / 10 < MIN_POINTS) ? MIN_POINTS : numPoints / 10;
+            numPointsChanged = true;
+            TraceLog(LOG_INFO, "num points %d", numPoints);
+        }
+
+        /* re-upload a different point cloud size */
+        if (numPointsChanged) {
+            UnloadModel(model);
+            mesh = GenMeshCustom(numPoints);
+            model = LoadModelFromMesh(mesh);
+            numPointsChanged = false;
+        }
 
         BeginDrawing();
             ClearBackground(BLACK);
             BeginMode3D(camera);
-                DrawModelPoints(model, position, 1.0f, WHITE);
+
-                if (drawSphere)
+                /* The new method only uploads the points once to the GPU */
-                    DrawSphereWires(position, 1.0f, 10, 10, WHITE);
+                if (newMethod) {
+                    DrawModelPoints(model, position, 1.0f, WHITE);
+                } else {
+                /* The old method must continually draw the "points" (lines) */
+                    for (int i = 0; i < numPoints; i++) {
+                        Vector3 pos = {
+                            .x = mesh.vertices[i * 3 + 0],
+                            .y = mesh.vertices[i * 3 + 1],
+                            .z = mesh.vertices[i * 3 + 2],
+                        };
+                        Color color = {
+                            .r = mesh.colors[i * 4 + 0],
+                            .g = mesh.colors[i * 4 + 1],
+                            .b = mesh.colors[i * 4 + 2],
+                            .a = mesh.colors[i * 4 + 3],
+                        };
+                        DrawPoint3D(pos, color);
+                    }
+                }
+
+                DrawSphereWires(position, 1.0f, 10, 10, YELLOW);
             EndMode3D();
+
+            /* Text formatting */
+            Color color = WHITE;
+            int fps = GetFPS();
+            if ((fps < 30) && (fps >= 15)) color = ORANGE;
+            else if (fps < 15) color = RED;
+            DrawText(TextFormat("%2i FPS", fps), 20, 20, 40, color);
+            DrawText(TextFormat("Point Count %d", numPoints), 20, 550, 40, WHITE);
+            DrawText("Up - increase points", 20, 70, 20, WHITE);
+            DrawText("Down - decrease points", 20, 100, 20, WHITE);
+            DrawText("Space - draw mode", 20, 130, 20, WHITE);
+            if (newMethod) {
+                DrawText("DrawModelPoints", 20, 160, 20, GREEN);
+            } else {
+                DrawText("DrawPoint3D", 20, 160, 20, RED);
+            }
         EndDrawing();
     }