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glview can now load static geometry modified by sparse accessor

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This commit is contained in:
Arthur Brainville (Ybalrid) 2019-03-06 14:48:44 +00:00
parent 9223d3133a
commit 14d259f361
1 changed files with 342 additions and 216 deletions
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146
examples/glview/glview.cc
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@ -28,7 +28,6 @@
#include "tiny_gltf.h"
#endif
#define BUFFER_OFFSET(i) ((char *)NULL + (i))
#define CheckGLErrors(desc) \
@ -55,7 +54,9 @@ float eye[3], lookat[3], up[3];
GLFWwindow *window;
typedef struct { GLuint vb; } GLBufferState;
typedef struct {
GLuint vb;
} GLBufferState;
typedef struct {
std::vector<GLuint> diffuseTex; // for each primitive in mesh
@ -254,6 +255,26 @@ void motionFunc(GLFWwindow *window, double mouse_x, double mouse_y) {
prevMouseY = mouse_y;
}
static size_t ComponentTypeByteSize(int type) {
switch (type) {
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE:
case TINYGLTF_COMPONENT_TYPE_BYTE:
return sizeof(char);
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT:
case TINYGLTF_COMPONENT_TYPE_SHORT:
return sizeof(short);
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_INT:
case TINYGLTF_COMPONENT_TYPE_INT:
return sizeof(int);
case TINYGLTF_COMPONENT_TYPE_FLOAT:
return sizeof(float);
case TINYGLTF_COMPONENT_TYPE_DOUBLE:
return sizeof(double);
default:
return 0;
}
}
static void SetupMeshState(tinygltf::Model &model, GLuint progId) {
// Buffer
{
@ -264,14 +285,117 @@ static void SetupMeshState(tinygltf::Model &model, GLuint progId) {
continue; // Unsupported bufferView.
}
int sparse_accessor = -1;
for (size_t a_i = 0; a_i < model.accessors.size(); ++a_i) {
const auto &accessor = model.accessors[a_i];
if (accessor.bufferView == i) {
std::cout << i << " is used by accessor " << a_i << std::endl;
if (accessor.sparse.isSparse) {
std::cout
<< "WARN: this bufferView has at least one sparse accessor to "
"it. We are going to load the data as patched by this "
"sparse accessor, not the original data"
<< std::endl;
sparse_accessor = a_i;
break;
}
}
}
const tinygltf::Buffer &buffer = model.buffers[bufferView.buffer];
GLBufferState state;
glGenBuffers(1, &state.vb);
glBindBuffer(bufferView.target, state.vb);
std::cout << "buffer.size= " << buffer.data.size()
<< ", byteOffset = " << bufferView.byteOffset << std::endl;
if (sparse_accessor < 0)
glBufferData(bufferView.target, bufferView.byteLength,
&buffer.data.at(0) + bufferView.byteOffset, GL_STATIC_DRAW);
&buffer.data.at(0) + bufferView.byteOffset,
GL_STATIC_DRAW);
else {
const auto accessor = model.accessors[sparse_accessor];
// copy the buffer to a temporary one for sparse patching
unsigned char *tmp_buffer = new unsigned char[bufferView.byteLength];
memcpy(tmp_buffer, buffer.data.data() + bufferView.byteOffset,
bufferView.byteLength);
const size_t size_of_object_in_buffer =
ComponentTypeByteSize(accessor.componentType);
const size_t size_of_sparse_indices =
ComponentTypeByteSize(accessor.sparse.indices.componentType);
const auto &indices_buffer_view =
model.bufferViews[accessor.sparse.indices.bufferView];
const auto &indices_buffer = model.buffers[indices_buffer_view.buffer];
const auto &values_buffer_view =
model.bufferViews[accessor.sparse.values.bufferView];
const auto &values_buffer = model.buffers[values_buffer_view.buffer];
for (size_t sparse_index = 0; sparse_index < accessor.sparse.count;
++sparse_index) {
int index = 0;
// std::cout << "accessor.sparse.indices.componentType = " <<
// accessor.sparse.indices.componentType << std::endl;
switch (accessor.sparse.indices.componentType) {
case TINYGLTF_COMPONENT_TYPE_BYTE:
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE:
index = (int)*(
unsigned char *)(indices_buffer.data.data() +
indices_buffer_view.byteOffset +
accessor.sparse.indices.byteOffset +
(sparse_index * size_of_sparse_indices));
break;
case TINYGLTF_COMPONENT_TYPE_SHORT:
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT:
index = (int)*(
unsigned short *)(indices_buffer.data.data() +
indices_buffer_view.byteOffset +
accessor.sparse.indices.byteOffset +
(sparse_index * size_of_sparse_indices));
break;
case TINYGLTF_COMPONENT_TYPE_INT:
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_INT:
index = (int)*(
unsigned int *)(indices_buffer.data.data() +
indices_buffer_view.byteOffset +
accessor.sparse.indices.byteOffset +
(sparse_index * size_of_sparse_indices));
break;
}
std::cout << "updating sparse data at index : " << index
<< std::endl;
// index is now the target of the sparse index to patch in
const unsigned char *read_from =
values_buffer.data.data() +
(values_buffer_view.byteOffset +
accessor.sparse.values.byteOffset) +
(sparse_index * (size_of_object_in_buffer * accessor.type));
/*
std::cout << ((float*)read_from)[0] << "\n";
std::cout << ((float*)read_from)[1] << "\n";
std::cout << ((float*)read_from)[2] << "\n";
*/
unsigned char *write_to =
tmp_buffer + index * (size_of_object_in_buffer * accessor.type);
memcpy(write_to, read_from, size_of_object_in_buffer * accessor.type);
}
// debug:
/*for(size_t p = 0; p < bufferView.byteLength/sizeof(float); p++)
{
float* b = (float*)tmp_buffer;
std::cout << "modified_buffer [" << p << "] = " << b[p] << '\n';
}*/
glBufferData(bufferView.target, bufferView.byteLength, tmp_buffer,
GL_STATIC_DRAW);
delete[] tmp_buffer;
}
glBindBuffer(bufferView.target, 0);
gBufferState[i] = state;
@ -558,12 +682,13 @@ static void DrawMesh(tinygltf::Model &model, const tinygltf::Mesh &mesh) {
(it->first.compare("TEXCOORD_0") == 0)) {
if (gGLProgramState.attribs[it->first] >= 0) {
// Compute byteStride from Accessor + BufferView combination.
int byteStride = accessor.ByteStride(model.bufferViews[accessor.bufferView]);
int byteStride =
accessor.ByteStride(model.bufferViews[accessor.bufferView]);
assert(byteStride != -1);
glVertexAttribPointer(gGLProgramState.attribs[it->first], size,
accessor.componentType, accessor.normalized ? GL_TRUE : GL_FALSE,
byteStride,
BUFFER_OFFSET(accessor.byteOffset));
accessor.componentType,
accessor.normalized ? GL_TRUE : GL_FALSE,
byteStride, BUFFER_OFFSET(accessor.byteOffset));
CheckErrors("vertex attrib pointer");
glEnableVertexAttribArray(gGLProgramState.attribs[it->first]);
CheckErrors("enable vertex attrib array");
@ -752,7 +877,8 @@ int main(int argc, char **argv) {
#ifdef _WIN32
#ifdef _DEBUG
std::string input_filename(argv[1] ? argv[1] : "../../../models/Cube/Cube.gltf");
std::string input_filename(argv[1] ? argv[1]
: "../../../models/Cube/Cube.gltf");
#endif
#else
std::string input_filename(argv[1] ? argv[1] : "../../models/Cube/Cube.gltf");
@ -763,7 +889,8 @@ int main(int argc, char **argv) {
bool ret = false;
if (ext.compare("glb") == 0) {
// assume binary glTF.
ret = loader.LoadBinaryFromFile(&model, &err, &warn, input_filename.c_str());
ret =
loader.LoadBinaryFromFile(&model, &err, &warn, input_filename.c_str());
} else {
// assume ascii glTF.
ret = loader.LoadASCIIFromFile(&model, &err, &warn, input_filename.c_str());
@ -833,7 +960,6 @@ int main(int argc, char **argv) {
const char *shader_vert_filename = "shader.vert";
#endif
if (false == LoadShader(GL_VERTEX_SHADER, vertId, shader_vert_filename)) {
return -1;
}