Created Notepad as IDE (markdown)

Notepad-as-IDE.md

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+
+#include "raylib.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+typedef struct {
+    float x, y, z;
+} Point3D;
+
+typedef struct {
+    int p, q;
+    int n, m;
+    float *U, *V;
+    float **w;
+    Point3D **P;
+} NURBSSurface;
+
+float Nip(int i, int p, float u, float *U) {
+    if (p == 0)
+        return (u >= U[i] && u < U[i+1]) ? 1.0f : 0.0f;
+
+    float denom1 = U[i+p] - U[i];
+    float denom2 = U[i+p+1] - U[i+1];
+
+    float term1 = denom1 != 0.0f ? (u - U[i]) / denom1 * Nip(i, p - 1, u, U) : 0.0f;
+    float term2 = denom2 != 0.0f ? (U[i+p+1] - u) / denom2 * Nip(i + 1, p - 1, u, U) : 0.0f;
+
+    return term1 + term2;
+}
+
+Point3D surfacePoint(NURBSSurface *surf, float u, float v) {
+    Point3D S = {0, 0, 0};
+    float denom = 0.0f;
+
+    for (int i = 0; i <= surf->n; i++) {
+        float Ni = Nip(i, surf->p, u, surf->U);
+        for (int j = 0; j <= surf->m; j++) {
+            float Nj = Nip(j, surf->q, v, surf->V);
+            float w = surf->w[i][j];
+            float B = Ni * Nj * w;
+
+            S.x += B * surf->P[i][j].x;
+            S.y += B * surf->P[i][j].y;
+            S.z += B * surf->P[i][j].z;
+            denom += B;
+        }
+    }
+
+    S.x /= denom;
+    S.y /= denom;
+    S.z /= denom;
+
+    return S;
+}
+
+void drawSurface(NURBSSurface *surf, int resolution) {
+    for (int i = 0; i < resolution; i++) {
+        float u = (float)i / (resolution - 1);
+        for (int j = 0; j < resolution; j++) {
+            float v = (float)j / (resolution - 1);
+            Point3D pt = surfacePoint(surf, u, v);
+            DrawSphere((Vector3){pt.x, pt.y, pt.z}, 0.03f, RED);
+        }
+    }
+}
+
+void freeSurface(NURBSSurface *surf) {
+    for (int i = 0; i <= surf->n; i++) {
+        free(surf->w[i]);
+        free(surf->P[i]);
+    }
+    free(surf->w);
+    free(surf->P);
+    free(surf->U);
+    free(surf->V);
+}
+
+int main(void) {
+    const int screenWidth = 800;
+    const int screenHeight = 600;
+
+    InitWindow(screenWidth, screenHeight, "NURBS Surface with Raylib");
+    Camera3D camera = {0};
+    camera.position = (Vector3){ 4.0f, 4.0f, 10.0f };
+    camera.target = (Vector3){ 2.0f, 2.0f, 0.0f };
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
+    camera.fovy = 45.0f;
+    camera.projection = CAMERA_PERSPECTIVE;
+
+    NURBSSurface surf = {0};
+    surf.p = 2;
+    surf.q = 2;
+    surf.n = 3;
+    surf.m = 3;
+
+    surf.U = (float[]){0,0,0,1,2,2,2};
+    surf.V = (float[]){0,0,0,1,2,2,2};
+
+    surf.w = malloc((surf.n+1) * sizeof(float *));
+    surf.P = malloc((surf.n+1) * sizeof(Point3D *));
+    for (int i = 0; i <= surf.n; i++) {
+        surf.w[i] = malloc((surf.m+1) * sizeof(float));
+        surf.P[i] = malloc((surf.m+1) * sizeof(Point3D));
+        for (int j = 0; j <= surf.m; j++) {
+            surf.w[i][j] = 1.0f;
+            surf.P[i][j] = (Point3D){(float)i, (float)j, (float)(i*j%3)};
+        }
+    }
+
+    SetTargetFPS(60);
+    while (!WindowShouldClose()) {
+        UpdateCamera(&camera, CAMERA_ORBITAL);
+
+        BeginDrawing();
+            ClearBackground(RAYWHITE);
+            BeginMode3D(camera);
+                drawSurface(&surf, 20);
+            EndMode3D();
+            DrawText("NURBS Surface", 10, 10, 20, DARKGRAY);
+        EndDrawing();
+    }
+
+    freeSurface(&surf);
+    CloseWindow();
+
+    return 0;
+}