From 15543a7b91359333e204cbff6641b01f0d24e9fe Mon Sep 17 00:00:00 2001
From: Charlie Birks <charlie@daft.games>
Date: Sat, 4 Nov 2023 22:13:43 +0000
Subject: [PATCH] Add texture support to models

---
 assets/cube.bin | Bin 876 -> 1020 bytes
 model-conv.py   |  40 ++++++++++++++++++++++++++++++++++++----
 model.cpp       |   9 ++++++++-
 model.hpp       |   3 ++-
 4 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/assets/cube.bin b/assets/cube.bin
index 2a90295f77f79f5f5134bcadc00692bfd27a5310..3ac7bcf1f8e7bbdd2f291acd8a41e91fabea93a2 100644
GIT binary patch
literal 1020
zcmaiy%MpVx3`9*Oxuk;>z)U8`^x#sU6H1|!l%i<$v1AC&!2`@=S1ZZS_v1B{Qto_8
zA@W0bEz`>1A6mfhm-56mWv-j}kEENS8?lk6v(9rP@jNoFvQT2+t`k;Ocg&(Xq&(-$
zO#QAs&-H$JVw&u_$%tewp)*#4X;#d$>2}fcfJbcP3C51$SxG!q<BXpRpBlRjov~Zo
ziKy3fGjh78@4-BUA^(-9vrc#G_pUuyKD&cnuVdDO*7E%|UCXI8F_$xooW_!;)=av?
gJ<}{Qjg|Ml<IVf)SlR=4$5MY+?4M`!U|FPxFWO&Yd;kCd

literal 876
zcma)(Q4Yf(3`4_Rc7xqu+UM@n-kim;tUx;GkZ7xi>p0={dA^&OJ$#$>uHAi^wKK3m
z!Lyl5-~4pculUMGy!uq`DGnq8=Vo2;TKA6ceD3`<9nL28GiN5`{Ex4Ez~M6bP%Ex(
zGY|F2rPrJ}P0bQ-{E>QmXWc8WdTLQWR@~KiU%xnOT=grSd6d59PaeIXpIDLP#IyG0
Q4#DUAQ11E8Cv(c@3%K<lVgLXD

diff --git a/model-conv.py b/model-conv.py
index 55780f5..8e21ec9 100644
--- a/model-conv.py
+++ b/model-conv.py
@@ -90,6 +90,10 @@ def handle_mesh(filename, json_data, json_mesh, matrix):
         if 'COLOR_0' in prim_attribs:
             colour_accessor = accessors[prim_attribs['COLOR_0']]
 
+        tex_coord_accessor = None
+        if 'TEXCOORD_0' in prim_attribs:
+            tex_coord_accessor = accessors[prim_attribs['TEXCOORD_0']]
+
         # TODO: may not exist, non-indexed data
         index_accessor = accessors[primitive['indices']]
 
@@ -103,25 +107,53 @@ def handle_mesh(filename, json_data, json_mesh, matrix):
         else:
             colour_data = np.full((len(position_data), 4), [1, 1, 1, 1])
 
+        # get tex coords or all zeros
+        if tex_coord_accessor:
+            tex_coord_data = get_accessor_data(filename, json_data, tex_coord_accessor)
+        else:
+            tex_coord_data = np.full((len(position_data), 2), [0, 0])
+
         index_data = get_accessor_data(filename, json_data, index_accessor, False)
 
+        # check if material is textures
+        material_id = primitive['material']
+        material = json_data['materials'][material_id]
+
+        # TODO: other material types?
+        tex_id = 0 # no tex
+        if 'pbrMetallicRoughness' in material and 'baseColorTexture' in material['pbrMetallicRoughness']:
+            tex_id = material['pbrMetallicRoughness']['baseColorTexture']['index'] + 1
+
         # triangles
         for i in index_data:
-            # convert data
+            # transform pos/normal
             pos = matrix @ np.append(position_data[i], 1)
             nor = rot_matrix @ normal_data[i]
 
             pos[1] *= -1 # flip y
             nor[1] *= -1
 
+            tex_coord = tex_coord_data[i]
+
+            # make tex coords positive
+            if tex_coord[0] < 0.0:
+                tex_coord[0] = 1.0 - (tex_coord[0] % 1)
+            if tex_coord[1] < 0.0:
+                tex_coord[1] = 1.0 - (tex_coord[1] % 1)
+
+            # TODO: wrap >1?
+
+            # convert data
             pos = np.floor(pos * (1 << 16)).astype(int)
             nor = np.floor(nor * 0x7FFF).astype(int)
             col = np.floor(colour_data[i] * 0xFF).astype(int)
+            tex_coord = np.floor(tex_coord * 0xFFFF).astype(int)
 
-            packed_vertex = struct.pack('<3i4B3hxx',
+            packed_vertex = struct.pack('<3i4B3h2Hxx',
                                         pos[0], pos[1], pos[2], 
-                                        col[0], col[1], col[2], col[3],
-                                        nor[0], nor[1], nor[2])
+                                        col[0], col[1], col[2], tex_id,
+                                        nor[0], nor[1], nor[2],
+                                        tex_coord[0], tex_coord[1])
             
             out_vertices.append(packed_vertex)
 
diff --git a/model.cpp b/model.cpp
index d64d96e..ceeb927 100644
--- a/model.cpp
+++ b/model.cpp
@@ -44,7 +44,14 @@ void model_lit_shader(const uint8_t *in, Render3D::VertexOutData *out, const Ren
     out->g = int32_t(dot * vertex->g);
     out->b = int32_t(dot * vertex->b);
 
-    out->tex_index = 0;
+    out->tex_index = vertex->tex_index;
+
+    if(vertex->tex_index)
+    {
+        // close enough (should be / 65535)
+        out->u = Fixed16<12>(Fixed32<>::from_raw(vertex->u));
+        out->v = Fixed16<12>(Fixed32<>::from_raw(vertex->v));
+    }
 }
 
 Model::Model(const uint8_t *asset_data)
diff --git a/model.hpp b/model.hpp
index 928d7bb..4346c8f 100644
--- a/model.hpp
+++ b/model.hpp
@@ -11,8 +11,9 @@ class Model final
     struct Vertex
     {
         uint32_t x, y, z;
-        uint8_t r, g, b, a;
+        uint8_t r, g, b, tex_index;
         int16_t nx, ny, nz;
+        uint16_t u, v;
         uint16_t pad;
     };