Add a ground. Add support for multiple objects and materials in MDL

1 files changed, 56 insertions, 4 deletions

diff --git a/include/model.h b/include/model.h
index 0730809..10c9cdf 100644
--- a/include/model.h
+++ b/include/model.h
@@ -1,9 +1,15 @@
 #pragma once
 
+#include <assert.h>
 #include <stddef.h>
 #include <stdint.h>
 
-constexpr size_t ModelPathLen = 256;
+constexpr size_t ModelPathLen      = 256;
+constexpr size_t ModelNameLen      = 64;
+constexpr size_t ModelMaxObjects   = 256; // uint8_t
+constexpr size_t ModelMaxMaterials = 256; // uint8_t
+constexpr size_t ModelMaxVerts     = 4294967296; // uint32_t
+constexpr size_t ModelMaxFaces     = 4294967296; // uint32_t
 
 typedef uint16_t mdIdx;
 typedef struct mdVert { mdIdx position, texcoord, normal; } mdVert;
@@ -11,9 +17,18 @@ typedef struct mdTri  { mdVert v0, v1, v2; } mdTri;
 typedef struct mdVec2 { float x, y;        } mdVec2;
 typedef struct mdVec3 { float x, y, z;     } mdVec3;
 
-typedef struct Material {
+typedef struct ModelObject {
+  uint32_t offset;   // FlatModel: offset into indices. IndexedModel: offset into tris.
+  uint32_t count;    // FloatModel: number of indices.  IndexedModel: number of tris.
+  uint8_t  material; // Material index.
+  uint8_t  pad[3];
+  char     name[ModelNameLen];
+} ModelObject;
+
+typedef struct ModelMaterial {
+  char name[ModelNameLen];
   char diffuseTexture[ModelPathLen];
-} Material;
+} ModelMaterial;
 
 // Every three indices form a triangle, and each index indexes all attribute
 // arrays simultaneously. This is best for a fast, linear-scan rendering.
@@ -28,6 +43,8 @@ typedef struct FlatModel {
   uint32_t offsetTexcoords;
   uint32_t offsetNormals;
   /*
+  [objects]   -- numObjects   Object
+  [materials] -- numMaterials Material
   [indices]   -- numIdxs  mdIdx
   [positions] -- numVerts mdVec3
   [texcoords] -- numVerts mdVec2
@@ -53,6 +70,8 @@ typedef struct IndexedModel {
   uint32_t offsetTexcoords;
   uint32_t offsetNormals;
   /*
+  [objects]   -- numObjects   Object
+  [materials] -- numMaterials Material
   [triangles] -- numTris      mdTri
   [positions] -- numPositions mdVec3
   [texcoords] -- numTexcoords mdVec2
@@ -68,9 +87,42 @@ typedef enum ModelType {
 
 typedef struct Model {
   uint32_t type;
-  Material material;
+  // Counts.
+  uint8_t  numObjects;
+  uint8_t  numMaterials;
+  uint8_t  pad[2];
+  // Offsets.
+  uint32_t offsetObjects;
+  uint32_t offsetMaterials;
+  // Model details.
   union {
     FlatModel    flat;
     IndexedModel indexed;
   };
 } Model;
+
+static inline const ModelObject* modelObjects(const Model* model) {
+  assert(model);
+  switch (model->type) {
+  case ModelTypeIndexed:
+    return (const ModelObject*)(model->indexed.data + model->offsetObjects);
+  case ModelTypeFlat:
+    return (const ModelObject*)(model->flat.data    + model->offsetObjects);
+  default:
+    assert(false);
+    break;
+  }
+}
+
+static inline const ModelMaterial* modelMaterials(const Model* model) {
+  assert(model);
+  switch (model->type) {
+  case ModelTypeIndexed:
+    return (const ModelMaterial*)(model->indexed.data + model->offsetMaterials);
+  case ModelTypeFlat:
+    return (const ModelMaterial*)(model->flat.data    + model->offsetMaterials);
+  default:
+    assert(false);
+    break;
+  }
+}