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Scene.cpp
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Scene.cpp
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#include "Scene.hpp"
#include "gl_errors.hpp"
#include "read_write_chunk.hpp"
#include <glm/gtc/type_ptr.hpp>
#include <fstream>
//-------------------------
Scene::Transform global_trans;
glm::mat4 Scene::Transform::make_local_to_parent() const {
return glm::mat4( //translate
glm::vec4(1.0f, 0.0f, 0.0f, 0.0f),
glm::vec4(0.0f, 1.0f, 0.0f, 0.0f),
glm::vec4(0.0f, 0.0f, 1.0f, 0.0f),
glm::vec4(position, 1.0f)
)
* glm::mat4_cast(rotation) //rotate
* glm::mat4( //scale
glm::vec4(scale.x, 0.0f, 0.0f, 0.0f),
glm::vec4(0.0f, scale.y, 0.0f, 0.0f),
glm::vec4(0.0f, 0.0f, scale.z, 0.0f),
glm::vec4(0.0f, 0.0f, 0.0f, 1.0f)
);
}
glm::mat4 Scene::Transform::make_parent_to_local() const {
glm::vec3 inv_scale;
inv_scale.x = (scale.x == 0.0f ? 0.0f : 1.0f / scale.x);
inv_scale.y = (scale.y == 0.0f ? 0.0f : 1.0f / scale.y);
inv_scale.z = (scale.z == 0.0f ? 0.0f : 1.0f / scale.z);
return glm::mat4( //un-scale
glm::vec4(inv_scale.x, 0.0f, 0.0f, 0.0f),
glm::vec4(0.0f, inv_scale.y, 0.0f, 0.0f),
glm::vec4(0.0f, 0.0f, inv_scale.z, 0.0f),
glm::vec4(0.0f, 0.0f, 0.0f, 1.0f)
)
* glm::mat4_cast(glm::inverse(rotation)) //un-rotate
* glm::mat4( //un-translate
glm::vec4(1.0f, 0.0f, 0.0f, 0.0f),
glm::vec4(0.0f, 1.0f, 0.0f, 0.0f),
glm::vec4(0.0f, 0.0f, 1.0f, 0.0f),
glm::vec4(-position, 1.0f)
);
}
glm::mat4 Scene::Transform::make_local_to_world() const {
if (!parent) {
return make_local_to_parent();
} else {
return parent->make_local_to_world() * make_local_to_parent();
}
}
glm::mat4 Scene::Transform::make_world_to_local() const {
if (!parent) {
return make_parent_to_local();
} else {
return make_parent_to_local() * parent->make_world_to_local();
}
}
//-------------------------
glm::mat4 Scene::Camera::make_projection() const {
return glm::infinitePerspective( fovy, aspect, near );
}
//-------------------------
void Scene::draw(Camera const &camera) const {
assert(camera.transform);
glm::mat4 world_to_clip = camera.make_projection() * camera.transform->make_world_to_local();
glm::mat4x3 world_to_light = glm::mat4x3(1.0f);
draw(world_to_clip, world_to_light);
}
void Scene::draw(Camera const &camera, Transform const &trans) const{
auto pos = global_trans.position;
auto rot = global_trans.rotation;
auto sc = global_trans.scale;
global_trans.position = trans.position;
global_trans.rotation = trans.rotation;
global_trans.scale = trans.scale;
global_trans.parent = nullptr;
draw(camera);
global_trans.position = pos;
global_trans.rotation = rot;
global_trans.scale = sc;
}
void Scene::draw(glm::mat4 const &world_to_clip, glm::mat4x3 const &world_to_light) const {
//Iterate through all drawables, sending each one to OpenGL:
for (auto const &drawable : drawables) {
//Reference to drawable's pipeline for convenience:
Scene::Drawable::Pipeline const &pipeline = drawable.pipeline;
//skip any drawables without a shader program set:
if (pipeline.program == 0) continue;
//skip any drawables that don't contain any vertices:
if (pipeline.count == 0) continue;
//Set shader program:
glUseProgram(pipeline.program);
//Set attribute sources:
glBindVertexArray(pipeline.vao);
//Configure program uniforms:
//the object-to-world matrix is used in all three of these uniforms:
assert(drawable.transform); //drawables *must* have a transform
glm::mat4 object_to_world = drawable.transform->make_local_to_world();
//OBJECT_TO_CLIP takes vertices from object space to clip space:
if (pipeline.OBJECT_TO_CLIP_mat4 != -1U) {
glm::mat4 object_to_clip = world_to_clip * object_to_world;
glUniformMatrix4fv(pipeline.OBJECT_TO_CLIP_mat4, 1, GL_FALSE, glm::value_ptr(object_to_clip));
}
//the object-to-light matrix is used in the next two uniforms:
glm::mat4x3 object_to_light = world_to_light * object_to_world;
//OBJECT_TO_CLIP takes vertices from object space to light space:
if (pipeline.OBJECT_TO_LIGHT_mat4x3 != -1U) {
glUniformMatrix4x3fv(pipeline.OBJECT_TO_LIGHT_mat4x3, 1, GL_FALSE, glm::value_ptr(object_to_light));
}
//NORMAL_TO_CLIP takes normals from object space to light space:
if (pipeline.NORMAL_TO_LIGHT_mat3 != -1U) {
glm::mat3 normal_to_light = glm::inverse(glm::transpose(glm::mat3(object_to_light)));
glUniformMatrix3fv(pipeline.NORMAL_TO_LIGHT_mat3, 1, GL_FALSE, glm::value_ptr(normal_to_light));
}
//set any requested custom uniforms:
if (pipeline.set_uniforms) pipeline.set_uniforms();
//set up textures:
for (uint32_t i = 0; i < Drawable::Pipeline::TextureCount; ++i) {
if (pipeline.textures[i].texture != 0) {
glActiveTexture(GL_TEXTURE0 + i);
glBindTexture(pipeline.textures[i].target, pipeline.textures[i].texture);
}
}
//draw the object:
glDrawArrays(pipeline.type, pipeline.start, pipeline.count);
//un-bind textures:
for (uint32_t i = 0; i < Drawable::Pipeline::TextureCount; ++i) {
if (pipeline.textures[i].texture != 0) {
glActiveTexture(GL_TEXTURE0 + i);
glBindTexture(pipeline.textures[i].target, 0);
}
}
glActiveTexture(GL_TEXTURE0);
}
glUseProgram(0);
glBindVertexArray(0);
GL_ERRORS();
}
void Scene::load(std::string const &filename,
std::function< void(Scene &, Transform *, std::string const &) > const &on_drawable) {
std::ifstream file(filename, std::ios::binary);
std::vector< char > names;
read_chunk(file, "str0", &names);
struct HierarchyEntry {
uint32_t parent;
uint32_t name_begin;
uint32_t name_end;
glm::vec3 position;
glm::quat rotation;
glm::vec3 scale;
};
static_assert(sizeof(HierarchyEntry) == 4 + 4 + 4 + 4*3 + 4*4 + 4*3, "HierarchyEntry is packed.");
std::vector< HierarchyEntry > hierarchy;
read_chunk(file, "xfh0", &hierarchy);
struct MeshEntry {
uint32_t transform;
uint32_t name_begin;
uint32_t name_end;
};
static_assert(sizeof(MeshEntry) == 4 + 4 + 4, "MeshEntry is packed.");
std::vector< MeshEntry > meshes;
read_chunk(file, "msh0", &meshes);
struct CameraEntry {
uint32_t transform;
char type[4]; //"pers" or "orth"
float data; //fov in degrees for 'pers', scale for 'orth'
float clip_near, clip_far;
};
static_assert(sizeof(CameraEntry) == 4 + 4 + 4 + 4 + 4, "CameraEntry is packed.");
std::vector< CameraEntry > cameras;
read_chunk(file, "cam0", &cameras);
struct LightEntry {
uint32_t transform;
char type;
glm::u8vec3 color;
float energy;
float distance;
float fov;
};
static_assert(sizeof(LightEntry) == 4 + 1 + 3 + 4 + 4 + 4, "LightEntry is packed.");
std::vector< LightEntry > lamps;
read_chunk(file, "lmp0", &lamps);
if (file.peek() != EOF) {
std::cerr << "WARNING: trailing data in scene file '" << filename << "'" << std::endl;
}
//--------------------------------
//Now that file is loaded, create transforms for hierarchy entries:
std::vector< Transform * > hierarchy_transforms;
hierarchy_transforms.reserve(hierarchy.size());
for (auto const &h : hierarchy) {
transforms.emplace_back();
Transform *t = &transforms.back();
if (h.parent != -1U) {
if (h.parent >= hierarchy_transforms.size()) {
throw std::runtime_error("scene file '" + filename + "' did not contain transforms in topological-sort order.");
}
t->parent = hierarchy_transforms[h.parent];
}
else {
t->parent = &global_trans;
}
if (h.name_begin <= h.name_end && h.name_end <= names.size()) {
t->name = std::string(names.begin() + h.name_begin, names.begin() + h.name_end);
} else {
throw std::runtime_error("scene file '" + filename + "' contains hierarchy entry with invalid name indices");
}
t->position = h.position;
t->rotation = h.rotation;
t->scale = h.scale;
hierarchy_transforms.emplace_back(t);
}
assert(hierarchy_transforms.size() == hierarchy.size());
for (auto const &m : meshes) {
if (m.transform >= hierarchy_transforms.size()) {
throw std::runtime_error("scene file '" + filename + "' contains mesh entry with invalid transform index (" + std::to_string(m.transform) + ")");
}
if (!(m.name_begin <= m.name_end && m.name_end <= names.size())) {
throw std::runtime_error("scene file '" + filename + "' contains mesh entry with invalid name indices");
}
std::string name = std::string(names.begin() + m.name_begin, names.begin() + m.name_end);
if (on_drawable) {
on_drawable(*this, hierarchy_transforms[m.transform], name);
}
}
for (auto const &c : cameras) {
if (c.transform >= hierarchy_transforms.size()) {
throw std::runtime_error("scene file '" + filename + "' contains camera entry with invalid transform index (" + std::to_string(c.transform) + ")");
}
if (std::string(c.type, 4) != "pers") {
std::cout << "Ignoring non-perspective camera (" + std::string(c.type, 4) + ") stored in file." << std::endl;
continue;
}
this->cameras.emplace_back(hierarchy_transforms[c.transform]);
hierarchy_transforms[c.transform]->parent = nullptr;
Camera *camera = &this->cameras.back();
camera->fovy = c.data / 180.0f * 3.1415926f; //FOV is stored in degrees; convert to radians.
camera->near = c.clip_near;
//N.b. far plane is ignored because cameras use infinite perspective matrices.
}
for (auto const &l : lamps) {
if (l.transform >= hierarchy_transforms.size()) {
throw std::runtime_error("scene file '" + filename + "' contains lamp entry with invalid transform index (" + std::to_string(l.transform) + ")");
}
if (l.type == 'p') {
//good
} else if (l.type == 'h') {
//fine
} else if (l.type == 's') {
//okay
} else if (l.type == 'd') {
//sure
} else {
std::cout << "Ignoring unrecognized lamp type (" + std::string(&l.type, 1) + ") stored in file." << std::endl;
continue;
}
this->lamps.emplace_back(hierarchy_transforms[l.transform]);
Lamp *lamp = &this->lamps.back();
lamp->type = static_cast<Lamp::Type>(l.type);
lamp->energy = glm::vec3(l.color) * l.energy;
lamp->spot_fov = l.fov / 180.0f * 3.1415926f; //FOV is stored in degrees; convert to radians.
}
}
//-------------------------