void Renderer::frustum_cull(glm::vec3 camera_position, SceneObject *object,
float frustum[6][4], std::vector<SceneObject*>& scene_objects,
bool need_cull, int planeMask) {
// frustumCull() return 3 possible values:
// 0 when the HBV of the object is completely outside the frustum: cull itself and all its children out
// 1 when the HBV of the object is intersecting the frustum but the object itself is not: cull it out and continue culling test with its children
// 2 when the HBV of the object is intersecting the frustum and the mesh BV of the object are intersecting (inside) the frustum: render itself and continue culling test with its children
// 3 when the HBV of the object is completely inside the frustum: render itself and all its children without further culling test
int cullVal;
if (need_cull) {
cullVal = object->frustumCull(camera_position, frustum, planeMask);
if (cullVal == 0) {
return;
}
if (cullVal >= 2) {
scene_objects.push_back(object);
}
if (cullVal == 3) {
need_cull = false;
}
} else {
scene_objects.push_back(object);
}
const std::vector<SceneObject*> children = object->children();
for (auto it = children.begin(); it != children.end(); ++it) {
frustum_cull(camera_position, *it, frustum, scene_objects, need_cull, planeMask);
}
}
void Renderer::frustum_cull(glm::vec3 camera_position, SceneObject *object,
float frustum[6][4], std::vector<SceneObject*>& scene_objects,
bool need_cull, int planeMask) {
// frustumCull() return 3 possible values:
// 0 when the HBV of the object is completely outside the frustum: cull itself and all its children out
// 1 when the HBV of the object is intersecting the frustum but the object itself is not: cull it out and continue culling test with its children
// 2 when the HBV of the object is intersecting the frustum and the mesh BV of the object are intersecting (inside) the frustum: render itself and continue culling test with its children
// 3 when the HBV of the object is completely inside the frustum: render itself and all its children without further culling test
int cullVal;
if (!object->enabled()) {
return;
}
//allows for on demand calculation of the camera distance; usually matters
//when transparent objects are in play
RenderData* renderData = object->render_data();
if (nullptr != renderData) {
renderData->setCameraDistanceLambda([object, camera_position]() {
// Transform the bounding volume
BoundingVolume bounding_volume_ = object->getBoundingVolume();
glm::vec4 transformed_sphere_center(bounding_volume_.center(), 1.0f);
// Calculate distance from camera
glm::vec4 position(camera_position, 1.0f);
glm::vec4 difference = transformed_sphere_center - position;
float distance = glm::dot(difference, difference);
// this distance will be used when sorting transparent objects
return distance;
});
}
if (need_cull) {
cullVal = object->frustumCull(camera_position, frustum, planeMask);
if (cullVal == 0) {
object->setCullStatus(true);
return;
}
if (cullVal >= 2) {
object->setCullStatus(false);
scene_objects.push_back(object);
}
if (cullVal == 3) {
object->setCullStatus(false);
need_cull = false;
}
} else {
object->setCullStatus(false);
scene_objects.push_back(object);
}
const std::vector<SceneObject*> children = object->children();
for (auto it = children.begin(); it != children.end(); ++it) {
frustum_cull(camera_position, *it, frustum, scene_objects, need_cull, planeMask);
}
}
/*
* Perform view frustum culling from a specific camera viewpoint
*/
void Renderer::cullFromCamera(Scene *scene, Camera* camera,
ShaderManager* shader_manager)
{
std::vector<SceneObject*> scene_objects;
glm::mat4 view_matrix = camera->getViewMatrix();
glm::mat4 projection_matrix = camera->getProjectionMatrix();
glm::mat4 vp_matrix = glm::mat4(projection_matrix * view_matrix);
glm::vec3 campos(view_matrix[3]);
scene_objects.reserve(1024);
scene_objects.clear();
render_data_vector.clear();
// Travese all scene objects in the scene as a tree and do frustum culling at the same time if enabled
// 1. Build the view frustum
float frustum[6][4];
build_frustum(frustum, (const float*) glm::value_ptr(vp_matrix));
// 2. Iteratively execute frustum culling for each root object (as well as its children objects recursively)
SceneObject *object = scene->getRoot();
if (DEBUG_RENDERER) {
LOGD("FRUSTUM: start frustum culling for root %s\n", object->name().c_str());
}
// frustum_cull(camera->owner_object()->transform()->position(), object, frustum, scene_objects, scene->get_frustum_culling(), 0);
frustum_cull(campos, object, frustum, scene_objects, scene->get_frustum_culling(), 0);
if (DEBUG_RENDERER) {
LOGD("FRUSTUM: end frustum culling for root %s\n", object->name().c_str());
}
// 3. do occlusion culling, if enabled
occlusion_cull(scene, scene_objects, shader_manager, vp_matrix);
}
/*
* Perform view frustum culling from a specific camera viewpoint
*/
void Renderer::cullFromCamera(Scene *scene, Camera* camera,
ShaderManager* shader_manager,
std::vector<SceneObject*>& scene_objects) {
render_data_vector.clear();
scene_objects.clear();
glm::mat4 view_matrix = camera->getViewMatrix();
glm::mat4 projection_matrix = camera->getProjectionMatrix();
glm::mat4 vp_matrix = glm::mat4(projection_matrix * view_matrix);
// 1. Travese all scene objects in the scene as a tree and do frustum culling at the same time if enabled
if (scene->get_frustum_culling()) {
if (DEBUG_RENDERER) {
LOGD("FRUSTUM: start frustum culling\n");
}
// 1. Build the view frustum
float frustum[6][4];
build_frustum(frustum, (const float*) glm::value_ptr(vp_matrix));
// 2. Iteratively execute frustum culling for each root object (as well as its children objects recursively)
std::vector<SceneObject*> root_objects = scene->scene_objects();
for (auto it = root_objects.begin(); it != root_objects.end(); ++it) {
SceneObject *object = *it;
if (DEBUG_RENDERER) {
LOGD("FRUSTUM: start frustum culling for root %s\n",
object->name().c_str());
}
frustum_cull(camera->owner_object()->transform()->position(), object, frustum, scene_objects, true, 0);
if (DEBUG_RENDERER) {
LOGD("FRUSTUM: end frustum culling for root %s\n",
object->name().c_str());
}
}
if (DEBUG_RENDERER) {
LOGD("FRUSTUM: end frustum culling\n");
}
}
else
scene_objects = scene->getWholeSceneObjects();
// 2. do occlusion culling, if enabled
occlusion_cull(scene, scene_objects, shader_manager, vp_matrix);
}
int main()
{
int exit_flag = 0, i;
MAT16F tmat;
VEC3F pos = vec3f(0.0, 0.0, 0.5), ang = vec3f(0.0, 0.0, 0.0);
MD2_MODEL mdl;
VERTEX *model_verts;
TRI *model_tris;
if(load_md2("data/babe.md2", &mdl))
{
allegro_message("Error: I need the MD2 model, stupid!");
exit(1);
}
convert_md2_to_base(&model_verts, &model_tris, &mdl, 0.02);
init();
LOCK_VARIABLE(fps);
LOCK_VARIABLE(frame_count);
LOCK_FUNCTION(update_fps);
install_int(update_fps, 1000);
float frame = 0.0;
int flag = 0, flag2 = 0;
int anim_flag = 0, point_flag = 0;
while(!exit_flag)
{
set_texture_mapping_mode(0);
if(key[KEY_ESC]) { exit_flag = 1; }
if(key[KEY_LEFT]) { pos.x -= 0.01; }
if(key[KEY_RIGHT]) { pos.x += 0.01; }
if(key[KEY_UP]) { pos.z += 0.02; }
if(key[KEY_DOWN]) { pos.z -= 0.02; }
if(key[KEY_SPACE]) { frame += 0.1; }
if(key[KEY_P]) { anim_flag = anim_flag ? 0 : 1; key[KEY_P] = 0; }
if(key[KEY_O]) { point_flag = point_flag ? 0 : 1; key[KEY_O] = 0; }
VEC2F mp, cp;
cp = vec2f(mouse_x, mouse_y);
if(mouse_b == 1)
{
if(flag == 0)
mp = cp;
flag = 1;
ang.y -= ((cp.x - mp.x) * 0.0002);
}
else
flag = 0;
if(mouse_b == 2)
{
if(flag2 == 0)
mp = cp;
flag2 = 1;
pos.z -= ((cp.y - mp.y) * 0.0002);
}
else
flag2 = 0;
ang.x = M_PI * 1.5;
convert_md2_frame_to_base(model_verts, &mdl, frame, 0.02);
if(anim_flag)
frame += 0.1 * (60.0 / (fps + 1.0));
reset_mat16f(tmat);
rotate_mat16f(tmat, ang.x, ang.y, ang.z);
translate_mat16f(tmat, pos.x, pos.y, pos.z);
for(i = 0; i < mdl.header.num_vertices; i++)
{
transform_vec3f(&model_verts[i].world, model_verts[i].local, tmat);
project_vertex(&model_verts[i]);
}
clear_bitmap(buffer);
clear_to_color(zbuffer, ZBUFFER_PRECISION);
for(i = 0; i < mdl.header.num_tris; i++)
{
update_tri_normal(&model_tris[i], model_verts);
frustum_cull(&model_tris[i], model_verts, -0.95, 20.0);
cull_backface(&model_tris[i], model_verts);
}
for(i = 0; i < mdl.header.num_tris; i++)
if(model_tris[i].vis)
my_triangle(buffer, model_verts, model_tris[i]);
if(point_flag)
for(i = 0; i < mdl.header.num_tris; i++)
if(model_tris[i].vis)
{
int x1 = model_verts[model_tris[i].a].sx, y1 = model_verts[model_tris[i].a].sy,
x2 = model_verts[model_tris[i].b].sx, y2 = model_verts[model_tris[i].b].sy,
x3 = model_verts[model_tris[i].c].sx, y3 = model_verts[model_tris[i].c].sy;
float z, z1 = model_verts[model_tris[i].a].screen.z,
z2 = model_verts[model_tris[i].b].screen.z,
z3 = model_verts[model_tris[i].c].screen.z;
if(on_bitmap(x1, y1, SCREEN_W, SCREEN_H))
{
z = (float)RI_PIXEL_Z(x1, y1) / (float)(ZBUFFER_PRECISION);
if(z1 < z + 0.001) circlefill(buffer, x1, y1, 1, makecol(255, 0, 0));
}
if(on_bitmap(x2, y2, SCREEN_W, SCREEN_H))
{
z = (float)RI_PIXEL_Z(x2, y2) / (float)(ZBUFFER_PRECISION);
if(z2 < z + 0.001) circlefill(buffer, x2, y2, 1, makecol(255, 0, 0));
}
if(on_bitmap(x3, y3, SCREEN_W, SCREEN_H))
{
z = (float)RI_PIXEL_Z(x3, y3) / (float)(ZBUFFER_PRECISION);
if(z3 < z + 0.001) circlefill(buffer, x3, y3, 1, makecol(255, 0, 0));
}
}
textprintf_ex(buffer, font, 10, 10, makecol(255, 255, 255), 0, "FPS: %d", fps);
blit(buffer, screen, 0, 0, 0, 0, SCREEN_W, SCREEN_H);
frame_count++;
}
free_md2(&mdl);
free(model_tris);
free(model_verts);
destroy_bitmap(texture);
destroy_bitmap(zbuffer);
destroy_bitmap(buffer);
deinit_renderer();
return 0;
}
void main()
{
tcPosition[ID] = vPosition[ID];
tcIndex[ID] = vIndex[ID];
tcTessCoord[ID] = vTessCoord[ID];
vec4 data = texelFetch(attribute_texture, int(vIndex[ID]) * 5);
if ( frustum_cull() ) {
if ( abs(vTessCoord[0].x - vTessCoord[1].x) * abs(vTessCoord[1].y - vTessCoord[2].y) == 1.0 ) {
vec4 curve_factor = clamp(texelFetch(attribute_texture, int(vIndex[ID]) * 5 + 4), 1, 4);
vec4 edgelen = control_polygon_length(parameter_texture, int(data.x), int(data.y), int(data.z));
// 2
// 2------3
//3 | | 1
// | |
// 0------1
// 0
float edge01 = edge_tesslevel(edgelen[0]);
float edge32 = edge_tesslevel(edgelen[2]);
float edge13 = edge_tesslevel(edgelen[1]);
float edge20 = edge_tesslevel(edgelen[3]);
//Following three must be same for Ist Pass
gl_TessLevelInner[0] = inner_tesslevel();
gl_TessLevelOuter[1] = edge01;
gl_TessLevelOuter[3] = edge32;
//Following three must be same for Ist Pass
gl_TessLevelInner[1] = inner_tesslevel();
gl_TessLevelOuter[0] = edge20;
gl_TessLevelOuter[2] = edge13;
} else {
vec4 point_on_plane0 = to_screen_space(vPosition[0]);
vec4 point_on_plane1 = to_screen_space(vPosition[1]);
vec4 point_on_plane2 = to_screen_space(vPosition[2]);
vec4 point_on_plane3 = to_screen_space(vPosition[3]);
//Approach I-----> For Outer Tessellation Levels : Take ratio according to the original control polygon length.
// For Inner Tessellation Levels : Evaluate the mid point of the patch and get the diagonal length.
vec4 edgelen = control_polygon_length(parameter_texture, int(data.x), int(data.y), int(data.z));
vec2 p1 = mix(vTessCoord[0].xy, vTessCoord[1].xy, 0.5);
vec2 p2 = mix(vTessCoord[3].xy, vTessCoord[2].xy, 0.5);
vec2 mid_uv = mix(p1, p2, 0.5);
vec4 du, dv, _puv;
HornerBernstein(parameter_texture, int(data.x), int(data.y), int(data.z), mid_uv, du, dv, _puv);
_puv = to_screen_space(_puv.xyz);
float length1 = length(point_on_plane0.xy - _puv.xy) + length(_puv.xy - point_on_plane3.xy);
float length2 = length(point_on_plane2.xy - _puv.xy) + length(_puv.xy - point_on_plane1.xy);
float diagonal_length = min(length1, length2);
float edge01 = edge_tesslevel(mix(edgelen[0], edgelen[2], abs(vTessCoord[0].y - vTessCoord[2].y)));
float edge32 = edge_tesslevel(mix(edgelen[0], edgelen[2], abs(vTessCoord[0].y - vTessCoord[2].y)));
float edge13 = edge_tesslevel(mix(edgelen[1], edgelen[3], abs(vTessCoord[0].x - vTessCoord[1].x)));
float edge20 = edge_tesslevel(mix(edgelen[1], edgelen[3], abs(vTessCoord[0].x - vTessCoord[1].x)));
/*****/
//Approach II-----> For Outer Tessellation Levels : Approximate the curvature length of the edge according to the angle between its normals.
// For Inner Tessellation Levels : Approximate the curvature of the surface according to the all edge normals.
//Normals projected in XY-Plane
/* vec2 normal0 = normalize(transpose(inverse(mat3(view_matrix * model_matrix))) * vNormal[0].xyz).xy;
vec2 normal1 = normalize(transpose(inverse(mat3(view_matrix * model_matrix))) * vNormal[1].xyz).xy;
vec2 normal2 = normalize(transpose(inverse(mat3(view_matrix * model_matrix))) * vNormal[2].xyz).xy;
vec2 normal3 = normalize(transpose(inverse(mat3(view_matrix * model_matrix))) * vNormal[3].xyz).xy;
float edge01 = edge_tesslevel(length(point_on_plane0 - point_on_plane1) * acos(dot(normal0, normal1)) / (2.0 * sin(acos(dot(normal0, normal1) / 2.0))));
float edge32 = edge_tesslevel(length(point_on_plane3 - point_on_plane2) * acos(dot(normal3, normal2)) / (2.0 * sin(acos(dot(normal3, normal2) / 2.0))));
float edge13 = edge_tesslevel(length(point_on_plane1 - point_on_plane3) * acos(dot(normal1, normal3)) / (2.0 * sin(acos(dot(normal1, normal3) / 2.0))));
float edge20 = edge_tesslevel(length(point_on_plane2 - point_on_plane0) * acos(dot(normal2, normal0)) / (2.0 * sin(acos(dot(normal2, normal0) / 2.0))));*/
//Following three must be same for Ist Pass
gl_TessLevelInner[0] = edge_tesslevel(diagonal_length);
gl_TessLevelOuter[1] = edge01;
gl_TessLevelOuter[3] = edge32;
//Following three must be same for Ist Pass
gl_TessLevelInner[1] = edge_tesslevel(diagonal_length);
gl_TessLevelOuter[0] = edge20;
gl_TessLevelOuter[2] = edge13;
}
} else {
gl_TessLevelInner[0] = 1;
gl_TessLevelOuter[1] = 1;
gl_TessLevelOuter[3] = 1;
gl_TessLevelInner[1] = 1;
gl_TessLevelOuter[0] = 1;
gl_TessLevelOuter[2] = 1;
}
}
