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Initial support of parsing vertex color(extension format)
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‎README.md‎

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Original file line numberDiff line numberDiff line change
@@ -89,6 +89,7 @@ TinyObjLoader is successfully used in ...
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* Group(parse multiple group name)
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* Vertex
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* Vertex color(as an extension: https://blender.stackexchange.com/questions/31997/how-can-i-get-vertex-painted-obj-files-to-import-into-blender)
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* Texcoord
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* Normal
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* Material
@@ -139,6 +140,13 @@ attrib_t::texcoords => 2 floats per vertex
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| u | v | u | v | u | v | u | v | .... | u | v |
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+-----------+-----------+-----------+-----------+ +-----------+
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attrib_t::colors => 3 floats per vertex(vertex color. optional)
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c[0] c[1] c[2] c[3] c[n-1]
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+-----------+-----------+-----------+-----------+ +-----------+
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| x | y | z | x | y | z | x | y | z | x | y | z | .... | x | y | z |
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+-----------+-----------+-----------+-----------+ +-----------+
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```
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Each `shape_t::mesh_t` does not contain vertex data but contains array index to `attrib_t`.
@@ -228,6 +236,10 @@ for (size_t s = 0; s < shapes.size(); s++) {
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tinyobj::real_t nz = attrib.normals[3*idx.normal_index+2];
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tinyobj::real_t tx = attrib.texcoords[2*idx.texcoord_index+0];
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tinyobj::real_t ty = attrib.texcoords[2*idx.texcoord_index+1];
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// Optional: vertex colors
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// tinyobj::real_t red = attrib.colors[3*idx.vertex_index+0];
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// tinyobj::real_t green = attrib.colors[3*idx.vertex_index+1];
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// tinyobj::real_t blue = attrib.colors[3*idx.vertex_index+2];
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}
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index_offset += fv;
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‎models/cube-vertexcol.obj‎

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@@ -0,0 +1,31 @@
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mtllib cube.mtl
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v 0.000000 2.000000 2.000000 0 0 0
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v 0.000000 0.000000 2.000000 0 0 1
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v 2.000000 0.000000 2.000000 0 1 0
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v 2.000000 2.000000 2.000000 0 1 1
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v 0.000000 2.000000 0.000000 1 0 0
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v 0.000000 0.000000 0.000000 1 0 1
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v 2.000000 0.000000 0.000000 1 1 0
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v 2.000000 2.000000 0.000000 1 1 1
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# 8 vertices
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g front cube
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usemtl white
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f 1 2 3 4
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g back cube
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# expects white material
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f 8 7 6 5
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g right cube
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usemtl red
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f 4 3 7 8
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g top cube
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usemtl white
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f 5 1 4 8
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g left cube
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usemtl green
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f 5 6 2 1
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g bottom cube
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usemtl white
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f 2 6 7 3
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# 6 elements

‎tests/tester.cc‎

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Original file line numberDiff line numberDiff line change
@@ -625,6 +625,39 @@ TEST_CASE("g_ignored", "[Issue138]") {
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}
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TEST_CASE("vertex-col-ext", "[Issue144]") {
629+
tinyobj::attrib_t attrib;
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std::vector<tinyobj::shape_t> shapes;
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std::vector<tinyobj::material_t> materials;
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std::string err;
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bool ret = tinyobj::LoadObj(&attrib, &shapes, &materials, &err, "../models/cube-vertexcol.obj", gMtlBasePath);
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if (!err.empty()) {
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std::cerr << err << std::endl;
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}
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PrintInfo(attrib, shapes, materials);
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REQUIRE(true == ret);
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REQUIRE((8 * 3) == attrib.colors.size());
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REQUIRE(0 == Approx(attrib.colors[3 * 0 + 0]));
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REQUIRE(0 == Approx(attrib.colors[3 * 0 + 1]));
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REQUIRE(0 == Approx(attrib.colors[3 * 0 + 2]));
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REQUIRE(0 == Approx(attrib.colors[3 * 1 + 0]));
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REQUIRE(0 == Approx(attrib.colors[3 * 1 + 1]));
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REQUIRE(1 == Approx(attrib.colors[3 * 1 + 2]));
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REQUIRE(1 == Approx(attrib.colors[3 * 4 + 0]));
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REQUIRE(1 == Approx(attrib.colors[3 * 7 + 0]));
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REQUIRE(1 == Approx(attrib.colors[3 * 7 + 1]));
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REQUIRE(1 == Approx(attrib.colors[3 * 7 + 2]));
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}
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#if 0
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int
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main(

‎tiny_obj_loader.h‎

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Original file line numberDiff line numberDiff line change
@@ -23,6 +23,7 @@ THE SOFTWARE.
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*/
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//
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// version 1.1.0 : Support parsing vertex color(#144)
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// version 1.0.8 : Fix parsing `g` tag just after `usemtl`(#138)
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// version 1.0.7 : Support multiple tex options(#126)
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// version 1.0.6 : Add TINYOBJLOADER_USE_DOUBLE option(#124)
@@ -230,6 +231,7 @@ typedef struct {
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std::vector<real_t> vertices; // 'v'
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std::vector<real_t> normals; // 'vn'
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std::vector<real_t> texcoords; // 'vt'
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std::vector<real_t> colors; // extension: vertex colors
233235
} attrib_t;
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235237
typedef struct callback_t_ {
@@ -602,6 +604,19 @@ static inline real_t parseReal(const char **token, double default_value = 0.0) {
602604
return f;
603605
}
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607+
static inline bool parseReal(const char **token, real_t *out) {
608+
(*token) += strspn((*token), " \t");
609+
const char *end = (*token) + strcspn((*token), " \t\r");
610+
double val;
611+
bool ret = tryParseDouble((*token), end, &val);
612+
if (ret) {
613+
real_t f = static_cast<real_t>(val);
614+
(*out) = f;
615+
}
616+
(*token) = end;
617+
return ret;
618+
}
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605620
static inline void parseReal2(real_t *x, real_t *y, const char **token,
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const double default_x = 0.0,
607622
const double default_y = 0.0) {
@@ -629,6 +644,23 @@ static inline void parseV(real_t *x, real_t *y, real_t *z, real_t *w,
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(*w) = parseReal(token, default_w);
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}
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647+
// Extension: parse vertex with colors(6 items)
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static inline bool parseVertexWithColor(real_t *x, real_t *y, real_t *z, real_t *r,
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real_t *g, real_t *b,
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const char **token, const double default_x = 0.0,
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const double default_y = 0.0,
652+
const double default_z = 0.0) {
653+
(*x) = parseReal(token, default_x);
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(*y) = parseReal(token, default_y);
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(*z) = parseReal(token, default_z);
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(*r) = parseReal(token, 1.0);
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(*g) = parseReal(token, 1.0);
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(*b) = parseReal(token, 1.0);
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return true;
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}
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632664
static inline bool parseOnOff(const char **token, bool default_value = true) {
633665
(*token) += strspn((*token), " \t");
634666
const char *end = (*token) + strcspn((*token), " \t\r");
@@ -1421,6 +1453,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
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attrib->vertices.clear();
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attrib->normals.clear();
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attrib->texcoords.clear();
1456+
attrib->colors.clear();
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shapes->clear();
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14261459
std::stringstream errss;
@@ -1453,6 +1486,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
14531486
std::vector<real_t> v;
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std::vector<real_t> vn;
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std::vector<real_t> vt;
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std::vector<real_t> vc;
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std::vector<tag_t> tags;
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std::vector<std::vector<vertex_index> > faceGroup;
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std::string name;
@@ -1495,10 +1529,15 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
14951529
if (token[0] == 'v' && IS_SPACE((token[1]))) {
14961530
token += 2;
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real_t x, y, z;
1498-
parseReal3(&x, &y, &z, &token);
1532+
real_t r, g, b;
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parseVertexWithColor(&x, &y, &z, &r, &g, &b, &token);
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v.push_back(x);
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v.push_back(y);
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v.push_back(z);
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vc.push_back(r);
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vc.push_back(g);
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vc.push_back(b);
15021541
continue;
15031542
}
15041543

@@ -1733,6 +1772,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
17331772
attrib->vertices.swap(v);
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attrib->normals.swap(vn);
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attrib->texcoords.swap(vt);
1775+
attrib->colors.swap(vc);
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17371777
return true;
17381778
}
@@ -1785,6 +1825,7 @@ bool LoadObjWithCallback(std::istream &inStream, const callback_t &callback,
17851825
// vertex
17861826
if (token[0] == 'v' && IS_SPACE((token[1]))) {
17871827
token += 2;
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// TODO(syoyo): Support parsing vertex color extension.
17881829
real_t x, y, z, w; // w is optional. default = 1.0
17891830
parseV(&x, &y, &z, &w, &token);
17901831
if (callback.vertex_cb) {

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