v/examples/sokol/06_obj_viewer/show_obj.v

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V

/**********************************************************************
*
* .obj viewer
*
* Copyright (c) 2021 Dario Deledda. All rights reserved.
* Use of this source code is governed by an MIT license
* that can be found in the LICENSE file.
*
* Example .obj model of V from SurmanPP
*
* HOW TO COMPILE SHADERS:
* Run `v shader .` in this directory to compile the shaders.
* For more info and help with shader compilation see `docs.md` and `v help shader`.
*
* ALTERNATIVE .OBJ MODELS:
* you can load alternative models putting them in the "assets/model" folder with or without their .mtl file.
* use the program help for further instructions.
*
* TODO:
* - frame counter
**********************************************************************/
import gg
import gg.m4
import gx
import math
import sokol.sapp
import sokol.gfx
import sokol.sgl
import time
import os
import obj
// GLSL Include and functions
#flag -I @VMODROOT/.
#include "gouraud.h" # Should be generated with `v shader .` (see the instructions at the top of this file)
fn C.gouraud_shader_desc(gfx.Backend) &C.sg_shader_desc
const (
win_width = 600
win_height = 600
bg_color = gx.white
)
struct App {
mut:
gg &gg.Context
texture C.sg_image
init_flag bool
frame_count int
mouse_x int = -1
mouse_y int = -1
scroll_y int // mouse wheel value
// time
ticks i64
// model
obj_part &obj.ObjPart
n_vertex u32
// init parameters
file_name string
single_material_flag bool
}
/******************************************************************************
* Draw functions
******************************************************************************/
[inline]
fn vec4(x f32, y f32, z f32, w f32) m4.Vec4 {
return m4.Vec4{
e: [x, y, z, w]!
}
}
fn calc_matrices(w f32, h f32, rx f32, ry f32, in_scale f32, pos m4.Vec4) obj.Mats {
proj := m4.perspective(60, w / h, 0.01, 100.0) // set far plane to 100 fro the zoom function
view := m4.look_at(vec4(f32(0.0), 0, 6, 0), vec4(f32(0), 0, 0, 0), vec4(f32(0), 1,
0, 0))
view_proj := view * proj
rxm := m4.rotate(m4.rad(rx), vec4(f32(1), 0, 0, 0))
rym := m4.rotate(m4.rad(ry), vec4(f32(0), 1, 0, 0))
model_pos := m4.unit_m4().translate(pos)
model_m := (rym * rxm) * model_pos
scale_m := m4.scale(vec4(in_scale, in_scale, in_scale, 1))
mv := scale_m * model_m // model view
nm := mv.inverse().transpose() // normal matrix
mvp := mv * view_proj // model view projection
return obj.Mats{
mv: mv
mvp: mvp
nm: nm
}
}
fn draw_model(app App, model_pos m4.Vec4) u32 {
if app.init_flag == false {
return 0
}
ws := gg.window_size_real_pixels()
dw := ws.width / 2
dh := ws.height / 2
mut scale := f32(1)
if app.obj_part.radius > 1 {
scale = 1 / (app.obj_part.radius)
} else {
scale = app.obj_part.radius
}
scale *= 3
// *** vertex shader uniforms ***
rot := [f32(app.mouse_y), f32(app.mouse_x)]
mut zoom_scale := scale + f32(app.scroll_y) / (app.obj_part.radius * 4)
mats := calc_matrices(dw, dh, rot[0], rot[1], zoom_scale, model_pos)
mut tmp_vs_param := obj.Tmp_vs_param{
mv: mats.mv
mvp: mats.mvp
nm: mats.nm
}
// *** fragment shader uniforms ***
time_ticks := f32(time.ticks() - app.ticks) / 1000
radius_light := f32(app.obj_part.radius)
x_light := f32(math.cos(time_ticks) * radius_light)
z_light := f32(math.sin(time_ticks) * radius_light)
mut tmp_fs_params := obj.Tmp_fs_param{}
tmp_fs_params.ligth = m4.vec3(x_light, radius_light, z_light)
sd := obj.Shader_data{
vs_data: unsafe { &tmp_vs_param }
vs_len: int(sizeof(tmp_vs_param))
fs_data: unsafe { &tmp_fs_params }
fs_len: int(sizeof(tmp_fs_params))
}
return app.obj_part.bind_and_draw_all(sd)
}
fn frame(mut app App) {
ws := gg.window_size_real_pixels()
// clear
mut color_action := C.sg_color_attachment_action{
action: gfx.Action(C.SG_ACTION_CLEAR)
value: C.sg_color{
r: 0.0
g: 0.0
b: 0.0
a: 1.0
}
}
mut pass_action := C.sg_pass_action{}
pass_action.colors[0] = color_action
gfx.begin_default_pass(&pass_action, ws.width, ws.height)
// render the data
draw_start_glsl(app)
draw_model(app, m4.Vec4{})
// uncoment if you want a raw benchmark mode
/*
mut n_vertex_drawn := u32(0)
n_x_obj := 20
for x in 0..n_x_obj {
for z in 0..30 {
for y in 0..4 {
n_vertex_drawn += draw_model(app, m4.Vec4{e:[f32((x-(n_x_obj>>1))*3),-3 + y*3,f32(-6*z),1]!})
}
}
}
*/
draw_end_glsl(app)
// println("v:$n_vertex_drawn")
app.frame_count++
}
fn draw_start_glsl(app App) {
if app.init_flag == false {
return
}
ws := gg.window_size_real_pixels()
gfx.apply_viewport(0, 0, ws.width, ws.height, true)
}
fn draw_end_glsl(app App) {
gfx.end_pass()
gfx.commit()
}
/******************************************************************************
* Init / Cleanup
******************************************************************************/
fn my_init(mut app App) {
mut object := &obj.ObjPart{}
obj_file_lines := obj.read_lines_from_file(app.file_name)
object.parse_obj_buffer(obj_file_lines, app.single_material_flag)
object.summary()
app.obj_part = object
// set max vertices,
// for a large number of the same type of object it is better use the instances!!
desc := sapp.create_desc()
gfx.setup(&desc)
sgl_desc := C.sgl_desc_t{
max_vertices: 128 * 65536
}
sgl.setup(&sgl_desc)
// 1x1 pixel white, default texture
unsafe {
tmp_txt := malloc(4)
tmp_txt[0] = byte(0xFF)
tmp_txt[1] = byte(0xFF)
tmp_txt[2] = byte(0xFF)
tmp_txt[3] = byte(0xFF)
app.texture = obj.create_texture(1, 1, tmp_txt)
free(tmp_txt)
}
// glsl
app.obj_part.init_render_data(app.texture)
app.init_flag = true
}
fn cleanup(mut app App) {
gfx.shutdown()
/*
for _, mat in app.obj_part.texture {
obj.destroy_texture(mat)
}
*/
}
/******************************************************************************
* events handling
******************************************************************************/
fn my_event_manager(mut ev gg.Event, mut app App) {
if ev.typ == .mouse_move {
app.mouse_x = int(ev.mouse_x)
app.mouse_y = int(ev.mouse_y)
}
if ev.scroll_y != 0 {
app.scroll_y += int(ev.scroll_y)
}
if ev.typ == .touches_began || ev.typ == .touches_moved {
if ev.num_touches > 0 {
touch_point := ev.touches[0]
app.mouse_x = int(touch_point.pos_x)
app.mouse_y = int(touch_point.pos_y)
}
}
}
/******************************************************************************
* Main
******************************************************************************/
// is needed for easier diagnostics on windows
[console]
fn main() {
/*
obj.tst()
exit(0)
*/
// App init
mut app := &App{
gg: 0
obj_part: 0
}
app.file_name = 'v.obj_' // default object is the v logo
app.single_material_flag = false
$if !android {
if os.args.len > 3 || (os.args.len >= 2 && os.args[1] in ['-h', '--help', '\\?', '-?']) {
eprintln('Usage:\nshow_obj [file_name:string] [single_material_flag:(true|false)]\n')
eprintln('file_name : name of the .obj file, it must be in the folder "assets/models"')
eprintln(' if no file name is passed the default V logo will be showed.')
eprintln(' if you want custom models you can put them in the folder "assets/models".')
eprintln("single_material_flag: if true the viewer use for all the model's parts the default material\n")
exit(0)
}
if os.args.len >= 2 {
app.file_name = os.args[1]
}
if os.args.len >= 3 {
app.single_material_flag = os.args[2].bool()
}
println('Loading model: $app.file_name')
println('Using single material: $app.single_material_flag')
}
app.gg = gg.new_context(
width: win_width
height: win_height
create_window: true
window_title: 'V Wavefront OBJ viewer - Use the mouse wheel to zoom'
user_data: app
bg_color: bg_color
frame_fn: frame
init_fn: my_init
cleanup_fn: cleanup
event_fn: my_event_manager
)
app.ticks = time.ticks()
app.gg.run()
}