From a3bc8aa65589cfd5f9db9dbd369503fd295acab1 Mon Sep 17 00:00:00 2001
From: Miloslav Ciz <drummyfish@disroot.org>
Date: Thu, 29 Aug 2024 23:59:54 +0200
Subject: [PATCH] Start model util

---
 assets/encodeCarModel.c | 142 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 assets/encodeCarModel.c

diff --git a/assets/encodeCarModel.c b/assets/encodeCarModel.c
new file mode 100644
index 0000000..33a5f94
--- /dev/null
+++ b/assets/encodeCarModel.c
@@ -0,0 +1,142 @@
+/**
+  Converts car 3D model in obj format to the game's internal C arrays. The model
+  is to be passed on stdin.
+
+  A specific subset of obj format is assumed. UVs must be present but not
+  normals or other such things.
+
+  The following materials must be set for model triangles: "a" for body, "b"
+  for rear wheels, "c" and "d" for front wheels.
+*/
+
+#include <stdio.h>
+
+#define UNIT 512
+#define ARRAY_MAX 1024
+
+int vertices[ARRAY_MAX * 3];
+int vertexTypes[ARRAY_MAX];
+int vertexCount;
+
+int uvs[ARRAY_MAX * 2];
+int uvCount;
+
+int triangles[ARRAY_MAX * 3];
+int triangleUvs[ARRAY_MAX * 3];
+int triangleCount;
+
+char line[128];
+
+void error(int n)
+{
+  printf("ERROR %d\n",n);
+  exit(1);
+}
+
+void writeArray(int *array, unsigned int len, const char *name,
+  unsigned int align)
+{
+  printf("%s[] =\n{",name);
+
+  for (int i = 0; i < len; ++i)
+  {
+    if (i != 0)
+      printf(", ");
+
+    if (i % align == 0)
+      printf("\n  ");
+
+    printf("%d",array[i]);
+  }
+
+  puts("\n};\n");
+}
+
+int main(void)
+{
+  unsigned char vertexType = 0;
+
+  while (1)
+  {
+    if (gets(line) == NULL)
+      break;
+
+    if (line[0] == 'f') // face
+    {
+       unsigned int n[6];
+
+       if (sscanf(line + 1,"%u/%u %u/%u %u/%u",
+         n,n + 1,n + 2,n + 3,n + 4,n + 5) != 6)
+         error(0);
+
+       triangles[triangleCount * 3] = n[0] - 1;
+       triangles[triangleCount * 3 + 1] = n[2] - 1;
+       triangles[triangleCount * 3 + 2] = n[4] - 1;
+
+       triangleUvs[triangleCount * 3] = n[1] - 1;
+       triangleUvs[triangleCount * 3 + 1] = n[3] - 1;
+       triangleUvs[triangleCount * 3 + 2] = n[5] - 1;
+
+       vertexTypes[n[0] - 1] = vertexType;
+       vertexTypes[n[1] - 1] = vertexType;
+       vertexTypes[n[2] - 1] = vertexType;
+
+       triangleCount++;
+
+       if (triangleCount >= ARRAY_MAX)
+         error(1);
+    }
+    else if (line[0] == 'v' && line[1] != 't') // vertex
+    {
+       float a, b, c;
+
+       if (sscanf(line + 1,"%f %f %f",&a,&b,&c) != 3)
+         error(2);
+
+       vertices[3 * vertexCount] = a * UNIT;
+       vertices[3 * vertexCount + 1] = b * UNIT;
+       vertices[3 * vertexCount + 2] = c * UNIT;
+
+       vertexCount++;
+
+       if (vertexCount >= ARRAY_MAX)
+         error(3);
+    }
+    else if (line[0] == 'v' && line[1] == 't') // texture vertex
+    {
+       float a, b;
+
+       if (sscanf(line + 2,"%f %f",&a,&b) != 2)
+         error(4);
+
+       uvs[2 * uvCount] = a * UNIT;
+       uvs[2 * uvCount + 1] = b * UNIT;
+
+       uvCount++;
+
+       if (uvCount >= ARRAY_MAX)
+         error(5);
+    }
+    else if (line[0] == 'u' && line[1] == 's') // material
+    {
+      vertexType = line[7] - 'a';
+    }
+  }
+
+  writeArray(vertices,vertexCount * 3,
+    "static const S3L_Unit LCR_carVertices",10);
+
+  writeArray(triangles,triangleCount * 3,
+    "static const S3L_Index LCR_carTriangles",13);
+
+  writeArray(uvs,uvCount * 2,
+    "static const S3L_Index LCR_carUvs",10);
+
+  writeArray(triangleUvs,triangleCount * 3,
+    "static const S3L_Index LCR_carTriangleUvs",13);
+
+  writeArray(vertexTypes,vertexCount,
+    "static const uint7_t LCR_carVertexTypes",18);
+
+  return 0;
+}