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v/vlib/gg/gg.v
2021-12-15 21:17:07 +03:00

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// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license that can be found in the LICENSE file.
module gg
import gx
import sokol.sapp
import sokol.sgl
import sokol.gfx
import math
pub type FNCb = fn (data voidptr)
pub type FNEvent = fn (e &Event, data voidptr)
pub type FNFail = fn (msg string, data voidptr)
pub type FNKeyDown = fn (c KeyCode, m Modifier, data voidptr)
pub type FNKeyUp = fn (c KeyCode, m Modifier, data voidptr)
pub type FNMove = fn (x f32, y f32, data voidptr)
pub type FNClick = fn (x f32, y f32, button MouseButton, data voidptr)
pub type FNUnClick = fn (x f32, y f32, button MouseButton, data voidptr)
pub type FNChar = fn (c u32, data voidptr)
pub struct Config {
pub:
width int
height int
use_ortho bool // unused, still here just for backwards compatibility
retina bool
resizable bool
user_data voidptr
font_size int
create_window bool
// window_user_ptr voidptr
window_title string
borderless_window bool
always_on_top bool
bg_color gx.Color
init_fn FNCb = voidptr(0)
frame_fn FNCb = voidptr(0)
native_frame_fn FNCb = voidptr(0)
cleanup_fn FNCb = voidptr(0)
fail_fn FNFail = voidptr(0)
//
event_fn FNEvent = voidptr(0)
quit_fn FNEvent = voidptr(0)
//
keydown_fn FNKeyDown = voidptr(0)
keyup_fn FNKeyUp = voidptr(0)
char_fn FNChar = voidptr(0)
//
move_fn FNMove = voidptr(0)
click_fn FNClick = voidptr(0)
unclick_fn FNUnClick = voidptr(0)
leave_fn FNEvent = voidptr(0)
enter_fn FNEvent = voidptr(0)
resized_fn FNEvent = voidptr(0)
scroll_fn FNEvent = voidptr(0)
// wait_events bool // set this to true for UIs, to save power
fullscreen bool
scale f32 = 1.0
sample_count int
swap_interval int = 1 // 1 = 60fps, 2 = 30fps etc. The preferred swap interval (ignored on some platforms)
// ved needs this
// init_text bool
font_path string
custom_bold_font_path string
ui_mode bool // refreshes only on events to save CPU usage
// font bytes for embedding
font_bytes_normal []byte
font_bytes_bold []byte
font_bytes_mono []byte
font_bytes_italic []byte
native_rendering bool // Cocoa on macOS/iOS, GDI+ on Windows
// drag&drop
enable_dragndrop bool // enable file dropping (drag'n'drop), default is false
max_dropped_files int = 1 // max number of dropped files to process (default: 1)
max_dropped_file_path_length int = 2048 // max length in bytes of a dropped UTF-8 file path (default: 2048)
}
pub struct PenConfig {
color gx.Color
line_type PenLineType = .solid
thickness int = 1
}
pub struct Size {
pub:
width int
height int
}
fn gg_frame_fn(user_data voidptr) {
mut ctx := unsafe { &Context(user_data) }
ctx.frame++
if ctx.config.frame_fn == voidptr(0) {
return
}
if ctx.native_rendering {
// return
}
ctx.record_frame()
if ctx.ui_mode && !ctx.needs_refresh {
// Draw 3 more frames after the "stop refresh" command
ctx.ticks++
if ctx.ticks > 3 {
return
}
}
ctx.config.frame_fn(ctx.user_data)
ctx.needs_refresh = false
}
pub fn (mut ctx Context) refresh_ui() {
ctx.needs_refresh = true
ctx.ticks = 0
}
fn gg_event_fn(ce voidptr, user_data voidptr) {
// e := unsafe { &sapp.Event(ce) }
mut e := unsafe { &Event(ce) }
mut g := unsafe { &Context(user_data) }
if g.ui_mode {
g.refresh_ui()
}
if e.typ == .mouse_down {
bitplace := int(e.mouse_button)
g.mbtn_mask |= byte(1 << bitplace)
g.mouse_buttons = MouseButtons(g.mbtn_mask)
}
if e.typ == .mouse_up {
bitplace := int(e.mouse_button)
g.mbtn_mask &= ~(byte(1 << bitplace))
g.mouse_buttons = MouseButtons(g.mbtn_mask)
}
if e.typ == .mouse_move && e.mouse_button == .invalid {
if g.mbtn_mask & 0x01 > 0 {
e.mouse_button = .left
}
if g.mbtn_mask & 0x02 > 0 {
e.mouse_button = .right
}
if g.mbtn_mask & 0x04 > 0 {
e.mouse_button = .middle
}
}
g.mouse_pos_x = int(e.mouse_x / g.scale)
g.mouse_pos_y = int(e.mouse_y / g.scale)
g.mouse_dx = int(e.mouse_dx / g.scale)
g.mouse_dy = int(e.mouse_dy / g.scale)
g.scroll_x = int(e.scroll_x / g.scale)
g.scroll_y = int(e.scroll_y / g.scale)
g.key_modifiers = Modifier(e.modifiers)
g.key_repeat = e.key_repeat
if e.typ in [.key_down, .key_up] {
key_idx := int(e.key_code) % key_code_max
prev := g.pressed_keys[key_idx]
next := e.typ == .key_down
g.pressed_keys[key_idx] = next
g.pressed_keys_edge[key_idx] = prev != next
}
if g.config.event_fn != voidptr(0) {
g.config.event_fn(e, g.config.user_data)
}
match e.typ {
.mouse_move {
if g.config.move_fn != voidptr(0) {
g.config.move_fn(e.mouse_x / g.scale, e.mouse_y / g.scale, g.config.user_data)
}
}
.mouse_down {
if g.config.click_fn != voidptr(0) {
g.config.click_fn(e.mouse_x / g.scale, e.mouse_y / g.scale, e.mouse_button,
g.config.user_data)
}
}
.mouse_up {
if g.config.unclick_fn != voidptr(0) {
g.config.unclick_fn(e.mouse_x / g.scale, e.mouse_y / g.scale, e.mouse_button,
g.config.user_data)
}
}
.mouse_leave {
if g.config.leave_fn != voidptr(0) {
g.config.leave_fn(e, g.config.user_data)
}
}
.mouse_enter {
if g.config.enter_fn != voidptr(0) {
g.config.enter_fn(e, g.config.user_data)
}
}
.mouse_scroll {
if g.config.scroll_fn != voidptr(0) {
g.config.scroll_fn(e, g.config.user_data)
}
}
.key_down {
if g.config.keydown_fn != voidptr(0) {
g.config.keydown_fn(e.key_code, Modifier(e.modifiers), g.config.user_data)
}
}
.key_up {
if g.config.keyup_fn != voidptr(0) {
g.config.keyup_fn(e.key_code, Modifier(e.modifiers), g.config.user_data)
}
}
.char {
if g.config.char_fn != voidptr(0) {
g.config.char_fn(e.char_code, g.config.user_data)
}
}
.resized {
if g.config.resized_fn != voidptr(0) {
g.config.resized_fn(e, g.config.user_data)
}
}
.quit_requested {
if g.config.quit_fn != voidptr(0) {
g.config.quit_fn(e, g.config.user_data)
}
}
else {
// dump(e)
}
}
}
fn gg_cleanup_fn(user_data voidptr) {
mut g := unsafe { &Context(user_data) }
if g.config.cleanup_fn != voidptr(0) {
g.config.cleanup_fn(g.config.user_data)
}
gfx.shutdown()
}
fn gg_fail_fn(msg &char, user_data voidptr) {
mut g := unsafe { &Context(user_data) }
vmsg := unsafe { tos3(msg) }
if g.config.fail_fn != voidptr(0) {
g.config.fail_fn(vmsg, g.config.user_data)
} else {
eprintln('gg error: $vmsg')
}
}
pub fn (ctx &Context) run() {
sapp.run(&ctx.window)
}
// Prepares the context for drawing
pub fn (gg &Context) begin() {
if gg.render_text && gg.font_inited {
gg.ft.flush()
}
sgl.defaults()
sgl.matrix_mode_projection()
sgl.ortho(0.0, f32(sapp.width()), f32(sapp.height()), 0.0, -1.0, 1.0)
}
// Finishes drawing for the context
pub fn (gg &Context) end() {
gfx.begin_default_pass(gg.clear_pass, sapp.width(), sapp.height())
sgl.draw()
gfx.end_pass()
gfx.commit()
/*
if gg.config.wait_events {
// println('gg: waiting')
wait_events()
}
*/
}
// quit closes the context window and exits the event loop for it
pub fn (ctx &Context) quit() {
sapp.request_quit() // does not require ctx right now, but sokol multi-window might in the future
}
pub fn (mut ctx Context) set_bg_color(c gx.Color) {
ctx.clear_pass = gfx.create_clear_pass(f32(c.r) / 255.0, f32(c.g) / 255.0, f32(c.b) / 255.0,
f32(c.a) / 255.0)
}
// Sets a pixel
[inline]
pub fn (ctx &Context) set_pixel(x f32, y f32, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_points()
sgl.v2f(x * ctx.scale, y * ctx.scale)
sgl.end()
}
// Sets pixels from an array of points [x, y, x2, y2, etc...]
[direct_array_access; inline]
pub fn (ctx &Context) set_pixels(points []f32, c gx.Color) {
assert points.len % 2 == 0
len := points.len / 2
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_points()
for i in 0 .. len {
x, y := points[i * 2], points[i * 2 + 1]
sgl.v2f(x * ctx.scale, y * ctx.scale)
}
sgl.end()
}
// Draws a filled triangle
pub fn (ctx &Context) draw_triangle(x f32, y f32, x2 f32, y2 f32, x3 f32, y3 f32, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_triangles()
sgl.v2f(x * ctx.scale, y * ctx.scale)
sgl.v2f(x2 * ctx.scale, y2 * ctx.scale)
sgl.v2f(x3 * ctx.scale, y3 * ctx.scale)
sgl.end()
}
// Draws the outline of a triangle
pub fn (ctx &Context) draw_empty_triangle(x f32, y f32, x2 f32, y2 f32, x3 f32, y3 f32, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_line_strip()
sgl.v2f(x * ctx.scale, y * ctx.scale)
sgl.v2f(x2 * ctx.scale, y2 * ctx.scale)
sgl.v2f(x3 * ctx.scale, y3 * ctx.scale)
sgl.v2f(x * ctx.scale, y * ctx.scale)
sgl.end()
}
// Draws a filled square
[inline]
pub fn (ctx &Context) draw_square(x f32, y f32, s f32, c gx.Color) {
ctx.draw_rect(x, y, s, s, c)
}
// Draws the outline of a square
[inline]
pub fn (ctx &Context) draw_empty_square(x f32, y f32, s f32, c gx.Color) {
ctx.draw_empty_rect(x, y, s, s, c)
}
// Draws the outline of a rectangle
pub fn (ctx &Context) draw_empty_rect(x f32, y f32, w f32, h f32, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_line_strip()
sgl.v2f(x * ctx.scale, y * ctx.scale)
sgl.v2f((x + w) * ctx.scale, y * ctx.scale)
sgl.v2f((x + w) * ctx.scale, (y + h) * ctx.scale)
sgl.v2f(x * ctx.scale, (y + h) * ctx.scale)
sgl.v2f(x * ctx.scale, (y - 1) * ctx.scale)
sgl.end()
}
// Draws a circle
pub fn (ctx &Context) draw_circle(x f32, y f32, r f32, c gx.Color) {
ctx.draw_circle_with_segments(x, y, r, 10, c)
}
// Draws a circle with a specific number of segments (affects how smooth/round the circle is)
pub fn (ctx &Context) draw_circle_with_segments(x f32, y f32, r f32, segments int, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
nx := x * ctx.scale
ny := y * ctx.scale
nr := r * ctx.scale
mut theta := f32(0)
mut xx := f32(0)
mut yy := f32(0)
sgl.begin_triangle_strip()
for i := 0; i < segments + 1; i++ {
theta = 2.0 * f32(math.pi) * f32(i) / f32(segments)
xx = nr * math.cosf(theta)
yy = nr * math.sinf(theta)
sgl.v2f(xx + nx, yy + ny)
sgl.v2f(nx, ny)
}
sgl.end()
}
// Draws a circle slice/pie.
pub fn (ctx &Context) draw_slice(x f32, y f32, r f32, start_angle f32, arc_angle f32, segments int, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
nx := x * ctx.scale
ny := y * ctx.scale
theta := f32(arc_angle / f32(segments))
tan_factor := math.tanf(theta)
rad_factor := math.cosf(theta)
mut xx := r * math.cosf(start_angle)
mut yy := r * math.sinf(start_angle)
sgl.begin_triangle_strip()
for i := 0; i < segments + 1; i++ {
sgl.v2f(xx + nx, yy + ny)
sgl.v2f(nx, ny)
tx := -yy
ty := xx
xx += tx * tan_factor
yy += ty * tan_factor
xx *= rad_factor
yy *= rad_factor
}
sgl.end()
}
// Draws the outline of a circle slice/pie.
pub fn (ctx &Context) draw_empty_slice(x f32, y f32, r f32, start_angle f32, arc_angle f32, segments int, c gx.Color) {
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
theta := f32(arc_angle / f32(segments))
tan_factor := math.tanf(theta)
rad_factor := math.cosf(theta)
nx := x * ctx.scale
ny := y * ctx.scale
mut xx := r * math.cosf(start_angle)
mut yy := r * math.sinf(start_angle)
sgl.begin_line_strip()
for i := 0; i < segments + 1; i++ {
sgl.v2f(xx + nx, yy + ny)
tx := -yy
ty := xx
xx += tx * tan_factor
yy += ty * tan_factor
xx *= rad_factor
yy *= rad_factor
}
sgl.end()
}
// Resize the context's Window
pub fn (mut ctx Context) resize(width int, height int) {
ctx.width = width
ctx.height = height
// C.sapp_resize_window(width, height)
}
// Draws a line between the points provided
pub fn (ctx &Context) draw_line(x f32, y f32, x2 f32, y2 f32, c gx.Color) {
$if macos {
if ctx.native_rendering {
// Make the line more clear on hi dpi screens: draw a rectangle
mut width := math.abs(x2 - x)
mut height := math.abs(y2 - y)
if width == 0 {
width = 1
} else if height == 0 {
height = 1
}
ctx.draw_rect(x, y, f32(width), f32(height), c)
return
}
}
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_line_strip()
sgl.v2f(x * ctx.scale, y * ctx.scale)
sgl.v2f(x2 * ctx.scale, y2 * ctx.scale)
sgl.end()
}
// Draws a line between the points provided with the PenConfig
pub fn (ctx &Context) draw_line_with_config(x f32, y f32, x2 f32, y2 f32, config PenConfig) {
if config.color.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
if config.thickness <= 0 {
return
}
nx := x * ctx.scale
ny := y * ctx.scale
nx2 := x2 * ctx.scale
ny2 := y2 * ctx.scale
dx := nx2 - nx
dy := ny2 - ny
length := math.sqrtf(math.powf(x2 - x, 2) + math.powf(y2 - y, 2))
theta := f32(math.atan2(dy, dx))
sgl.push_matrix()
sgl.translate(nx, ny, 0)
sgl.rotate(theta, 0, 0, 1)
sgl.translate(-nx, -ny, 0)
if config.line_type == .solid {
ctx.draw_rect(x, y, length, config.thickness, config.color)
} else {
size := if config.line_type == .dotted { config.thickness } else { config.thickness * 3 }
space := if size == 1 { 2 } else { size }
mut available := length
mut start_x := x
for i := 0; available > 0; i++ {
if i % 2 == 0 {
ctx.draw_rect(start_x, y, size, config.thickness, config.color)
available -= size
start_x += size
continue
}
available -= space
start_x += space
}
}
sgl.pop_matrix()
}
// Draws an arc
pub fn (ctx &Context) draw_arc(x f32, y f32, inner_r f32, outer_r f32, start_angle f32, end_angle f32, segments int, c gx.Color) {
if start_angle == end_angle || outer_r <= 0.0 {
return
}
mut r1 := inner_r
mut r2 := outer_r
mut a1 := start_angle
mut a2 := end_angle
// TODO: Maybe this does not make since inner_r and outer_r is actually integers?
if outer_r < inner_r {
r1, r2 = r2, r1
if r2 <= 0.0 {
r2 = 0.1
}
}
if a2 < a1 {
a1, a2 = a2, a1
}
if r1 <= 0.0 {
ctx.draw_slice(x, y, int(r2), a1, a2, segments, c)
return
}
mut step_length := (a2 - a1) / f32(segments)
mut angle := a1
sgl.begin_quads()
sgl.c4b(c.r, c.g, c.b, c.a)
for _ in 0 .. segments {
sgl.v2f(x + f32(math.sin(angle)) * r1, y + f32(math.cos(angle) * r1))
sgl.v2f(x + f32(math.sin(angle)) * r2, y + f32(math.cos(angle) * r2))
sgl.v2f(x + f32(math.sin(angle + step_length)) * r2, y + f32(math.cos(angle +
step_length) * r2))
sgl.v2f(x + f32(math.sin(angle + step_length)) * r1, y + f32(math.cos(angle +
step_length) * r1))
angle += step_length
}
sgl.end()
}
// Draws a filled rounded rectangle
pub fn (ctx &Context) draw_rounded_rect(x f32, y f32, w f32, h f32, radius f32, c gx.Color) {
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_triangle_strip()
mut theta := f32(0)
mut xx := f32(0)
mut yy := f32(0)
r := radius * ctx.scale
nx := x * ctx.scale
ny := y * ctx.scale
width := w * ctx.scale
height := h * ctx.scale
segments := 2 * math.pi * r
segdiv := segments / 4
rb := 0
lb := int(rb + segdiv)
lt := int(lb + segdiv)
rt := int(lt + segdiv)
// left top
lx := nx + r
ly := ny + r
for i in lt .. rt {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + lx, yy + ly)
sgl.v2f(lx, ly)
}
// right top
mut rx := nx + width - r
mut ry := ny + r
for i in rt .. int(segments) {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + rx, yy + ry)
sgl.v2f(rx, ry)
}
// right bottom
mut rbx := rx
mut rby := ny + height - r
for i in rb .. lb {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + rbx, yy + rby)
sgl.v2f(rbx, rby)
}
// left bottom
mut lbx := lx
mut lby := ny + height - r
for i in lb .. lt {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + lbx, yy + lby)
sgl.v2f(lbx, lby)
}
sgl.v2f(lx + xx, ly)
sgl.v2f(lx, ly)
sgl.end()
sgl.begin_quads()
sgl.v2f(lx, ly)
sgl.v2f(rx, ry)
sgl.v2f(rbx, rby)
sgl.v2f(lbx, lby)
sgl.end()
}
// Draws the outline of a rounded rectangle
pub fn (ctx &Context) draw_empty_rounded_rect(x f32, y f32, w f32, h f32, radius f32, c gx.Color) {
mut theta := f32(0)
mut xx := f32(0)
mut yy := f32(0)
r := radius * ctx.scale
nx := x * ctx.scale
ny := y * ctx.scale
width := w * ctx.scale
height := h * ctx.scale
segments := 2 * math.pi * r
segdiv := segments / 4
rb := 0
lb := int(rb + segdiv)
lt := int(lb + segdiv)
rt := int(lt + segdiv)
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_line_strip()
// left top
lx := nx + r
ly := ny + r
for i in lt .. rt {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + lx, yy + ly)
}
// right top
mut rx := nx + width - r
mut ry := ny + r
for i in rt .. int(segments) {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + rx, yy + ry)
}
// right bottom
mut rbx := rx
mut rby := ny + height - r
for i in rb .. lb {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + rbx, yy + rby)
}
// left bottom
mut lbx := lx
mut lby := ny + height - r
for i in lb .. lt {
theta = 2 * f32(math.pi) * f32(i) / segments
xx = r * math.cosf(theta)
yy = r * math.sinf(theta)
sgl.v2f(xx + lbx, yy + lby)
}
sgl.v2f(lx + xx, ly)
sgl.end()
}
// draw_convex_poly draws a convex polygon, given an array of points, and a color.
// Note that the points must be given in clockwise order.
pub fn (ctx &Context) draw_convex_poly(points []f32, c gx.Color) {
assert points.len % 2 == 0
len := points.len / 2
assert len >= 3
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_triangle_strip()
x0 := points[0] * ctx.scale
y0 := points[1] * ctx.scale
for i in 1 .. (len / 2 + 1) {
sgl.v2f(x0, y0)
sgl.v2f(points[i * 4 - 2] * ctx.scale, points[i * 4 - 1] * ctx.scale)
sgl.v2f(points[i * 4] * ctx.scale, points[i * 4 + 1] * ctx.scale)
}
if len % 2 == 0 {
sgl.v2f(points[2 * len - 2] * ctx.scale, points[2 * len - 1] * ctx.scale)
}
sgl.end()
}
// draw_empty_poly - draws the borders of a polygon, given an array of points, and a color.
// Note that the points must be given in clockwise order.
pub fn (ctx &Context) draw_empty_poly(points []f32, c gx.Color) {
assert points.len % 2 == 0
len := points.len / 2
assert len >= 3
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_line_strip()
for i in 0 .. len {
sgl.v2f(points[2 * i] * ctx.scale, points[2 * i + 1] * ctx.scale)
}
sgl.v2f(points[0] * ctx.scale, points[1] * ctx.scale)
sgl.end()
}
// draw_cubic_bezier draws a cubic Bézier curve, also known as a spline, from four points.
// The four points is provided as one `points` array which contains a stream of point pairs (x and y coordinates).
// Thus a cubic Bézier could be declared as: `points := [x1, y1, control_x1, control_y1, control_x2, control_y2, x2, y2]`.
// Please see `draw_cubic_bezier_in_steps` to control the amount of steps (segments) used to draw the curve.
pub fn (ctx &Context) draw_cubic_bezier(points []f32, c gx.Color) {
ctx.draw_cubic_bezier_in_steps(points, u32(30 * ctx.scale), c)
}
// draw_cubic_bezier_in_steps draws a cubic Bézier curve, also known as a spline, from four points.
// The smoothness of the curve can be controlled with the `steps` parameter. `steps` determines how many iterations is
// taken to draw the curve.
// The four points is provided as one `points` array which contains a stream of point pairs (x and y coordinates).
// Thus a cubic Bézier could be declared as: `points := [x1, y1, control_x1, control_y1, control_x2, control_y2, x2, y2]`.
pub fn (ctx &Context) draw_cubic_bezier_in_steps(points []f32, steps u32, c gx.Color) {
assert steps > 0
assert points.len == 8
if c.a != 255 {
sgl.load_pipeline(ctx.timage_pip)
}
sgl.c4b(c.r, c.g, c.b, c.a)
sgl.begin_line_strip()
p1_x, p1_y := points[0], points[1]
p2_x, p2_y := points[6], points[7]
ctrl_p1_x, ctrl_p1_y := points[2], points[3]
ctrl_p2_x, ctrl_p2_y := points[4], points[5]
// The constant 3 is actually points.len() - 1;
step := f32(1.0) / steps
sgl.v2f(p1_x * ctx.scale, p1_y * ctx.scale)
for u := f32(0.0); u <= f32(1.0); u += step {
pow_2_u := u * u
pow_3_u := pow_2_u * u
x := pow_3_u * (p2_x + 3 * (ctrl_p1_x - ctrl_p2_x) - p1_x) +
3 * pow_2_u * (p1_x - 2 * ctrl_p1_x + ctrl_p2_x) + 3 * u * (ctrl_p1_x - p1_x) + p1_x
y := pow_3_u * (p2_y + 3 * (ctrl_p1_y - ctrl_p2_y) - p1_y) +
3 * pow_2_u * (p1_y - 2 * ctrl_p1_y + ctrl_p2_y) + 3 * u * (ctrl_p1_y - p1_y) + p1_y
sgl.v2f(x * ctx.scale, y * ctx.scale)
}
sgl.v2f(p2_x * ctx.scale, p2_y * ctx.scale)
sgl.end()
}
// window_size returns the `Size` of the active window
pub fn window_size() Size {
s := dpi_scale()
return Size{int(sapp.width() / s), int(sapp.height() / s)}
}
// window_size_real_pixels returns the `Size` of the active window without scale
pub fn window_size_real_pixels() Size {
return Size{sapp.width(), sapp.height()}
}
pub fn dpi_scale() f32 {
mut s := sapp.dpi_scale()
$if android {
s *= android_dpi_scale()
}
// NB: on older X11, `Xft.dpi` from ~/.Xresources, that sokol uses,
// may not be set which leads to sapp.dpi_scale reporting incorrectly 0.0
if s < 0.1 {
s = 1.0
}
return s
}