add parseNodeTransform() for tinygltf nodes

include/asset.h

@@ -25,6 +25,10 @@ struct mesh
 	glm::mat4* xform;
 };
 
+// TODO: will eventually need a tree structure with child nodes and transforms
+// 	at each branch. Can then combine each transform down from the root node to
+// 	the mesh, and send the final combination down to the shader
+
 #define MAX_PATH_SIZE 256
 struct model
 {

src/asset.cpp

@@ -2,6 +2,7 @@
 #include <cassert>
 #include <cstring>
 
+#include <glm/ext/matrix_transform.hpp>
 #include "tiny_gltf.h"
 
 #include "asset.h"
@@ -168,7 +169,40 @@ copyBuffer(uint8_t*& buffer_ref,
 	buffer_ref = (uint8_t*) arenaAllocateBlock(arena, bv.byteLength);
 	std::memcpy(buffer_ref, &t_buf.data[bv.byteOffset], bv.byteLength);
 
-	return buffer_ref == nullptr;
+	return buffer_ref != nullptr;
+}
+
+glm::mat4*
+parseNodeTransform(memory_arena* arena, const tinygltf::Node* node)
+{
+	if (node->rotation.size() == 4
+		&& node->scale.size() == 3
+		&& node->translation.size() == 3)
+	{
+		glm::mat4* xform =
+			(glm::mat4*) arenaAllocateBlock(arena, sizeof(glm::mat4));
+		*xform = glm::mat4(1.0f);
+		*xform = glm::rotate(*xform, (float) node->rotation[3],
+			glm::vec3((float) node->rotation[0],
+				(float) node->rotation[1],
+				(float) node->rotation[2])
+		);
+		*xform = glm::scale(*xform,
+			glm::vec3((float) node->scale[0],
+				(float) node->scale[0],
+				(float) node->scale[0])
+		);
+		*xform = glm::translate(*xform,
+			glm::vec3((float) node->translation[0],
+				(float) node->translation[0],
+				(float) node->translation[0])
+		);
+
+		return xform;
+	}
+
+	LOG(Error) << "Unknown transform\n";
+	return nullptr;
 }
 
 bool
@@ -194,16 +228,29 @@ parseMeshNode(mesh& m,
 	m.num_vertices = vert_acc.count;
 	m.num_indices = index_acc.count;
 	m.draw_mode = prim.mode;
-	m.usage = GL_STATIC_DRAW; // TODO: logic for updating meshes
+	m.usage = GL_STATIC_DRAW; // TODO: logic for updating dynamic meshes
+	// FIXME: the node transforms from blender only work as part of a node tree
+#if 1
 	m.xform = (glm::mat4*) arenaAllocateBlock(arena, sizeof(glm::mat4));
-	copyBuffer(
-		(uint8_t*&) m.vertices, arena, prim.attributes["POSITION"], t_mdl);
-	copyBuffer((uint8_t*&) m.normals, arena, prim.attributes["NORMAL"], t_mdl);
-	copyBuffer((uint8_t*&) m.texture_coords,
-		arena, prim.attributes["TEXCOORD_0"], t_mdl);
-	copyBuffer((uint8_t*&) m.indices, arena, prim.indices, t_mdl);
-
+	*m.xform = glm::mat4(1.0f);
+#else
+	m.xform = parseNodeTransform(arena, &node);
+#endif
+
+	if (m.xform != nullptr
+		&& copyBuffer((uint8_t*&) m.vertices, arena,
+			prim.attributes["POSITION"], t_mdl)
+		&& copyBuffer((uint8_t*&) m.normals, arena,
+			prim.attributes["NORMAL"], t_mdl)
+		&& copyBuffer((uint8_t*&) m.texture_coords, arena,
+			prim.attributes["TEXCOORD_0"], t_mdl)
+		&& copyBuffer((uint8_t*&) m.indices, arena,
+			prim.indices, t_mdl))
+	{
 		return true;
+	}
+
+	return false;
 }
 
 model*
@@ -227,8 +274,8 @@ assetLoadFromFile(model_assets* assets,
 	// NOTE: assume we're working with a single buffer
 	assert(t_mdl.buffers.size() == 1);
 	model* mdl = initModel(assets, arena, t_mdl, filename);
-	// TODO: also need to get each node xform
-	// TODO: also need to dump textures/materials
+	// FIXME: also need to get each node xform
+	// FIXME: also need to dump textures/materials
 	//dumpNodes(t_mdl);
 
 	uint mesh_idx = 0;
@@ -236,8 +283,7 @@ assetLoadFromFile(model_assets* assets,
 	for (tinygltf::Node node : t_mdl.nodes) {
 		if (node.mesh >= 0) {
 			if (!parseMeshNode(mdl->meshes[mesh_idx++], arena, node, t_mdl)) {
-				// FIXME: error handling
-				LOG(Error) << "Some mesh parsing error\n";
+				LOG(Error) << "Error parsing node\n";
 				return nullptr;
 			}
 		}