Merge pull request #43 from mavlink/fix/release-build

fix: add dummy texcoords to OBJ models to prevent Release crash

Author: mrpollo

models/fpv_hexarotor.obj

@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+"""Add dummy texture coordinates to OBJ files that lack them.
+
+Raylib 5.5's OBJ loader crashes in Release builds when models use the
+"f v//vn" face format (no texture coordinate index). This script adds a
+single "vt 0.0 0.0" line after the last vertex normal and rewrites all
+faces from "f v//vn" to "f v/1/vn".
+
+Usage:
+    python3 scripts/fix_obj_texcoords.py models/my_model.obj
+    python3 scripts/fix_obj_texcoords.py models/*.obj
+"""
+import re
+import sys
+
+def fix_obj(path):
+    with open(path, 'r') as f:
+        lines = f.readlines()
+
+    has_vt = any(l.startswith('vt ') for l in lines)
+    has_bare = any('//' in l for l in lines if l.startswith('f '))
+
+    if has_vt and not has_bare:
+        print(f"  SKIP {path} (already has texcoords)")
+        return False
+
+    # Find last vn line and insert vt after it
+    last_vn = -1
+    for i, line in enumerate(lines):
+        if line.startswith('vn '):
+            last_vn = i
+
+    if last_vn == -1:
+        print(f"  SKIP {path} (no vertex normals)")
+        return False
+
+    if not has_vt:
+        lines.insert(last_vn + 1, 'vt 0.0 0.0\n')
+
+    # Replace f v//vn with f v/1/vn
+    fixed = 0
+    for i, line in enumerate(lines):
+        if line.startswith('f ') and '//' in line:
+            lines[i] = re.sub(r'(\d+)//(\d+)', r'\1/1/\2', line)
+            fixed += 1
+
+    with open(path, 'w') as f:
+        f.writelines(lines)
+
+    print(f"  FIXED {path} ({fixed} faces updated)")
+    return True
+
+
+if __name__ == '__main__':
+    if len(sys.argv) < 2:
+        print(__doc__)
+        sys.exit(1)
+
+    count = 0
+    for path in sys.argv[1:]:
+        if fix_obj(path):
+            count += 1
+
+    print(f"\n{count} file(s) fixed." if count else "\nNo files needed fixing.")

models/fpv_quadrotor.obj

@@ -17,3 +17,8 @@ add_executable(test_data_source test_data_source.c)
 target_link_libraries(test_data_source PRIVATE mavsim-core)
 target_compile_definitions(test_data_source PRIVATE FIXTURES_DIR="${FIXTURES_DIR}")
 add_test(NAME data_source COMMAND test_data_source)
+
+# OBJ model validation (catches missing texcoords that crash Raylib)
+add_executable(test_obj_models test_obj_models.c)
+target_compile_definitions(test_obj_models PRIVATE MODELS_DIR="${CMAKE_SOURCE_DIR}/models")
+add_test(NAME obj_models COMMAND test_obj_models)

models/px4_hexarotor.obj

@@ -0,0 +1,94 @@
+#include <assert.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#ifndef MODELS_DIR
+#define MODELS_DIR "models"
+#endif
+
+// Raylib 5.5's OBJ loader crashes when a model has no texture coordinates.
+// The face format "f v//vn" (skipping texcoord index) causes an out-of-bounds
+// read in tinyobj_loader_c. This only manifests in Release builds.
+//
+// To fix an OBJ exported without texcoords:
+//   1. Add a single "vt 0.0 0.0" line after the last "vn" line
+//   2. Change all faces from "f v//vn" to "f v/1/vn"
+//
+// Example sed one-liner (backup first!):
+//   sed -i 's|//|/1/|g' model.obj
+//   sed -i '/^vn /a vt 0.0 0.0' model.obj  (add after first vn block)
+
+static int failures = 0;
+
+static void check_obj(const char *path) {
+    FILE *f = fopen(path, "r");
+    if (!f) {
+        printf("  SKIP %s (not found)\n", path);
+        return;
+    }
+
+    int has_faces = 0;
+    int has_vt = 0;
+    int bare_face_line = 0;
+    int line_num = 0;
+    char line[512];
+
+    while (fgets(line, sizeof(line), f)) {
+        line_num++;
+        if (line[0] == 'f' && line[1] == ' ') {
+            has_faces = 1;
+            if (!bare_face_line && strstr(line, "//"))
+                bare_face_line = line_num;
+        }
+        if (line[0] == 'v' && line[1] == 't' && line[2] == ' ')
+            has_vt = 1;
+    }
+    fclose(f);
+
+    if (!has_faces) {
+        printf("  PASS %s (no faces)\n", path);
+        return;
+    }
+
+    if (!has_vt || bare_face_line) {
+        printf("\n  FAIL %s\n", path);
+        if (!has_vt)
+            printf("       Missing texture coordinates (no 'vt' lines).\n");
+        if (bare_face_line)
+            printf("       Uses 'f v//vn' format at line %d (missing texcoord index).\n", bare_face_line);
+        printf("       Raylib 5.5 will segfault in Release builds.\n");
+        printf("       Run: python3 scripts/fix_obj_texcoords.py %s\n\n", path);
+        failures++;
+        return;
+    }
+
+    printf("  PASS %s\n", path);
+}
+
+int main(void) {
+    printf("test_obj_models:\n");
+
+    DIR *dir = opendir(MODELS_DIR);
+    assert(dir && "Cannot open models directory");
+
+    struct dirent *entry;
+    while ((entry = readdir(dir)) != NULL) {
+        size_t len = strlen(entry->d_name);
+        if (len > 4 && strcmp(entry->d_name + len - 4, ".obj") == 0) {
+            char path[512];
+            snprintf(path, sizeof(path), "%s/%s", MODELS_DIR, entry->d_name);
+            check_obj(path);
+        }
+    }
+    closedir(dir);
+
+    if (failures > 0) {
+        printf("\n%d model(s) failed validation.\n", failures);
+        return 1;
+    }
+
+    printf("All OBJ models passed.\n");
+    return 0;
+}