a_chat_client/src/ui.h

570 lines
19 KiB
C

// A naive implementation of an immediate mode gui.
#ifndef ED_UI_INCLUDED
#define ED_UI_INCLUDED
#define MAX_UI_ELEMENTS 8192
// TODO: replace this with functions
#define _FONT_WIDTH 12
#define _FONT_HEIGHT 24
#define _elm(index) (cx->frame_elements.data + index)
#define _flags(index, flgs) ((_elm(index)->flags & (flgs)) == (flgs))
#define _first(index) (_elm(index)->first)
#define _last(index) (_elm(index)->last)
#define _next(index) (_elm(index)->next)
#define _prev(index) (_elm(index)->prev)
#define _parent(index) (_elm(index)->parent)
#define _first_ref(index) (_elm(_first(index)))
#define _last_ref(index) (_elm(_last(index)))
#define _next_ref(index) (_elm(_next(index)))
#define _prev_ref(index) (_elm(_prev(index)))
#define _parent_ref(index) (_elm(_parent(index)))
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include "ed_array.h"
#include "ht.h"
typedef enum {
UI_AXIS_HORIZONTAL,
UI_AXIS_VERTICAL,
} ui_axis;
typedef enum {
UI_SEMANTIC_SIZE_FIT_TEXT,
UI_SEMANTIC_SIZE_CHILDREN_SUM,
UI_SEMANTIC_SIZE_FILL,
UI_SEMANTIC_SIZE_EXACT,
UI_SEMANTIC_SIZE_PERCENT_OF_PARENT,
} ui_semantic_size_t;
typedef struct {
ui_semantic_size_t type;
union {
uint32_t integer;
};
} ui_semantic_size;
#define ui_make_size(horizontal, vertical) \
((ui_semantic_size[2]){horizontal, vertical})
#define ui_fit_text ((ui_semantic_size){.type = UI_SEMANTIC_SIZE_FIT_TEXT})
#define ui_fill ((ui_semantic_size){.type = UI_SEMANTIC_SIZE_FILL})
#define ui_children_sum \
((ui_semantic_size){.type = UI_SEMANTIC_SIZE_CHILDREN_SUM})
#define ui_exact(value) \
((ui_semantic_size){.type = UI_SEMANTIC_SIZE_EXACT, .integer = value})
typedef struct {
ui_axis axis;
ui_semantic_size semantic_size[2];
uint32_t computed_size[2];
uint32_t computed_pos[2];
} ui_size;
typedef struct {
bool hovering;
bool clicked;
bool dragging;
} ui_interaction;
// UI Element data persisted across frames
typedef struct {
string label;
ui_size size;
size_t last_instantiated_index;
} ui_element_cache_data;
typedef enum {
UI_FLAG_CLICKABLE = 0b000000001,
UI_FLAG_HOVERABLE = 0b000000010,
UI_FLAG_SCROLLABLE = 0b000000100,
UI_FLAG_DRAW_TEXT = 0b000001000,
UI_FLAG_DRAW_BORDER = 0b000010000,
UI_FLAG_DRAW_BACKGROUND = 0b000100000,
UI_FLAG_ROUNDED_BORDER = 0b001000000,
UI_FLAG_FLOATING = 0b010000000,
UI_FLAG_CUSTOM_DRAW_FUNC = 0b100000000,
} ui_flags;
// Ephemeral frame only UI Element data
typedef struct {
size_t index;
string key;
string label;
ui_size size;
ui_flags flags;
// optional types
size_t first;
size_t last;
size_t next;
size_t prev;
size_t parent;
} ui_element_frame_data;
arrayTemplate(ui_element_frame_data);
typedef struct {
bool mouse_left_down;
bool mouse_right_down;
uint32_t mouse_x;
uint32_t mouse_y;
} ui_context_input;
typedef struct {
ed_ht cached_elements;
array(ui_element_frame_data) frame_elements;
array(ui_element_frame_data) frame_floating_elements;
ui_context_input input;
ui_context_input last_input;
size_t frame_index;
uint32_t canvas_size[2];
size_t current_parent;
} ui_context;
void ui_compute_layout(ui_context *cx, size_t element_index);
ui_interaction _ui_test_interaction(ui_context *cx, size_t element_index);
ui_interaction ui_button(ui_context *cx, string label);
#ifdef ED_UI_IMPLEMENTATION
ui_context ui_init_context() {
ed_ht cached_elements =
ht_create(MAX_UI_ELEMENTS, sizeof(ui_element_cache_data));
array(ui_element_frame_data) frame_elements =
newArray(ui_element_frame_data, MAX_UI_ELEMENTS);
array(ui_element_frame_data) frame_floating_elements =
newArray(ui_element_frame_data, MAX_UI_ELEMENTS);
ui_element_frame_data frame_data = (ui_element_frame_data){
.index = 0,
// TODO: don't just set this to label, because then elements
// with the same label can't be created together
.key = _String("root"),
.label = _String("root"),
.first = -1,
.last = -1,
.next = -1,
.prev = -1,
.parent = -1,
.size = {
.axis = UI_AXIS_HORIZONTAL,
.computed_size = {640, 480},
}};
pushArray(ui_element_frame_data, &frame_elements, frame_data);
return (ui_context){
.cached_elements = cached_elements,
.frame_elements = frame_elements,
.frame_floating_elements = frame_floating_elements,
.frame_index = 0,
};
}
void ui_push_parent(ui_context *cx) {
if (cx->frame_elements.size > 0) {
cx->current_parent = cx->frame_elements.size - 1;
}
}
void ui_pop_parent(ui_context *cx) {
if (_parent(cx->current_parent) < SIZE_MAX) {
cx->current_parent = _parent(cx->current_parent);
}
}
size_t ui_element(ui_context *cx, string label, ui_axis axis,
ui_semantic_size size[2], ui_flags flags) {
ui_element_frame_data frame_data = (ui_element_frame_data){
.index = cx->frame_elements.size,
// TODO: don't just set this to label, because then elements
// with the same label can't be created together
.key = label,
.label = label,
.first = -1,
.last = -1,
.next = -1,
.prev = cx->frame_elements.data[cx->current_parent].last,
.parent = cx->current_parent,
.size.axis = axis,
.size.semantic_size[0] = size[0],
.size.semantic_size[1] = size[1],
.flags = flags,
};
// Get cached element data
ui_element_cache_data *cache_data = ht_get(&cx->cached_elements, label);
if (cache_data) {
cache_data->last_instantiated_index = cx->frame_index;
frame_data.size.computed_pos[0] = cache_data->size.computed_pos[0];
frame_data.size.computed_pos[1] = cache_data->size.computed_pos[1];
frame_data.size.computed_size[0] = cache_data->size.computed_size[0];
frame_data.size.computed_size[1] = cache_data->size.computed_size[1];
} else {
bool did_insert = ht_set(&cx->cached_elements, label,
&(ui_element_cache_data){
.label = label,
.size = {0},
.last_instantiated_index = cx->frame_index,
});
assert("couldn't insert into ui element cache" && did_insert);
}
pushArray(ui_element_frame_data, &cx->frame_elements, frame_data);
if (frame_data.prev < SIZE_MAX) {
_prev_ref(frame_data.index)->next = frame_data.index;
}
if (_elm(cx->current_parent)->first == SIZE_MAX) {
_elm(cx->current_parent)->first = frame_data.index;
}
_elm(cx->current_parent)->last = frame_data.index;
return frame_data.index;
}
ui_interaction _ui_test_interaction(ui_context *cx, size_t element_index) {
bool hovering = false;
bool mouse_is_clicked =
cx->last_input.mouse_left_down && !cx->input.mouse_left_down;
ui_element_frame_data *elm = _elm(element_index);
if ((cx->input.mouse_x >= elm->size.computed_pos[0] &&
cx->input.mouse_x <
elm->size.computed_pos[0] + elm->size.computed_size[0]) &&
cx->input.mouse_y >= elm->size.computed_pos[1] &&
cx->input.mouse_y <
elm->size.computed_pos[1] + elm->size.computed_size[1]) {
hovering = true;
}
return (ui_interaction){.hovering = hovering,
.clicked = hovering && mouse_is_clicked};
}
ui_interaction ui_button(ui_context *cx, string label) {
size_t id = ui_element(cx, label, UI_AXIS_HORIZONTAL,
ui_make_size(ui_fit_text, ui_fit_text),
UI_FLAG_DRAW_BACKGROUND | UI_FLAG_DRAW_TEXT |
UI_FLAG_HOVERABLE | UI_FLAG_CLICKABLE);
return _ui_test_interaction(cx, id);
}
static uint32_t _ui_ancestor_size(ui_context *cx, size_t element_index,
ui_axis axis) {
if (element_index == SIZE_MAX || _parent(element_index) == SIZE_MAX) {
return cx->frame_elements.data[0].size.computed_size[axis];
}
switch (_parent_ref(element_index)->size.semantic_size[axis].type) {
case UI_SEMANTIC_SIZE_FIT_TEXT:
case UI_SEMANTIC_SIZE_FILL:
case UI_SEMANTIC_SIZE_EXACT:
case UI_SEMANTIC_SIZE_PERCENT_OF_PARENT:
return _parent_ref(element_index)->size.computed_size[axis];
break;
case UI_SEMANTIC_SIZE_CHILDREN_SUM:
return _ui_ancestor_size(cx, _parent(element_index), axis);
break;
}
}
static void _ui_compute_simple_layout(ui_context *cx,
ui_element_frame_data *elm, ui_axis axis,
bool *post_compute) {
switch (elm->size.semantic_size[axis].type) {
case UI_SEMANTIC_SIZE_FIT_TEXT:
if (axis == UI_AXIS_HORIZONTAL) {
elm->size.computed_size[axis] = elm->label.len * _FONT_WIDTH;
} else if (axis == UI_AXIS_VERTICAL) {
elm->size.computed_size[axis] = _FONT_HEIGHT;
}
break;
case UI_SEMANTIC_SIZE_CHILDREN_SUM:
post_compute[axis] = true;
break;
case UI_SEMANTIC_SIZE_FILL:
// TODO: set to ancestor size for floating
break;
case UI_SEMANTIC_SIZE_EXACT:
elm->size.computed_size[axis] = elm->size.semantic_size[axis].integer;
break;
case UI_SEMANTIC_SIZE_PERCENT_OF_PARENT: {
float semantic_value = (float)elm->size.semantic_size[axis].integer;
elm->size.computed_size[axis] =
(uint32_t)((float)(_ui_ancestor_size(cx, elm->index, axis)) *
(semantic_value / 100.0));
} break;
}
}
static void _ui_compute_children_layout(ui_context *cx,
ui_element_frame_data *elm) {
uint32_t child_size[2] = {0, 0};
// NOTE: the number of fills for the opposite axis of this box needs to
// be 1 because it will never get incremented in the loop below and
// cause a divide by zero and the number of fills for the axis of the
// box needs to start at zero or else it will be n+1 causing incorrect
// sizes
uint32_t num_fills[2] = {1, 1};
num_fills[elm->size.axis] = 0;
// TODO: maybe just use the actual data instead of copying?
uint32_t elm_size[2] = {elm->size.computed_size[0],
elm->size.computed_size[1]};
size_t child_index = elm->first;
if (child_index < SIZE_MAX) {
do {
ui_compute_layout(cx, child_index);
if (_elm(child_index)->size.semantic_size[elm->size.axis].type ==
UI_SEMANTIC_SIZE_FILL) {
num_fills[elm->size.axis] += 1;
} else {
child_size[elm->size.axis] +=
_elm(child_index)->size.computed_size[elm->size.axis];
}
} while ((child_index = _next(child_index)) < SIZE_MAX);
}
child_index = elm->first;
if (child_index < SIZE_MAX) {
do {
for (size_t axis = 0; axis < 2; ++axis) {
if (_elm(child_index)->size.semantic_size[axis].type ==
UI_SEMANTIC_SIZE_FILL) {
_elm(child_index)->size.computed_size[axis] =
(elm_size[axis] - child_size[axis]) / num_fills[axis];
}
}
ui_compute_layout(cx, child_index);
} while ((child_index = _next(child_index)) < SIZE_MAX);
}
}
void ui_compute_layout(ui_context *cx, size_t element_index) {
if (element_index == SIZE_MAX)
return;
ui_axis axis = UI_AXIS_HORIZONTAL;
__auto_type elm = _elm(element_index);
if (_parent(element_index) < SIZE_MAX &&
!_flags(element_index, UI_FLAG_FLOATING)) {
__auto_type parent = _parent_ref(element_index);
axis = parent->size.axis;
elm->size.computed_pos[0] = parent->size.computed_pos[0];
elm->size.computed_pos[1] = parent->size.computed_pos[1];
// TODO: implement scrolling
// elm->size.computed_pos[axis] += parent.scroll_offset;
}
if (!_flags(element_index, UI_FLAG_FLOATING) &&
_prev(element_index) < SIZE_MAX) {
__auto_type prev = _prev_ref(element_index);
if (prev >= 0) {
elm->size.computed_pos[axis] =
prev->size.computed_pos[axis] + prev->size.computed_size[axis];
}
}
bool post_compute[2] = {false, false};
// only compute layout for children of root
if (elm->index > 0) {
for (int i = 0; i < 2; ++i) {
_ui_compute_simple_layout(cx, elm, i, post_compute);
}
}
_ui_compute_children_layout(cx, elm);
// NOTE(pcleavelin): the only difference between these two blocks is the
// ordering of the switch block they can probably be merged
if (post_compute[UI_AXIS_HORIZONTAL]) {
elm->size.computed_size[UI_AXIS_HORIZONTAL] = 0;
size_t child_index = elm->first;
if (child_index < SIZE_MAX) {
do {
__auto_type child = _elm(child_index);
switch (elm->size.axis) {
case UI_AXIS_HORIZONTAL:
elm->size.computed_size[UI_AXIS_HORIZONTAL] +=
child->size.computed_size[UI_AXIS_HORIZONTAL];
break;
case UI_AXIS_VERTICAL:
if (child->size.computed_size[UI_AXIS_HORIZONTAL] >
elm->size.computed_size[UI_AXIS_HORIZONTAL]) {
elm->size.computed_size[UI_AXIS_HORIZONTAL] =
child->size.computed_size[UI_AXIS_HORIZONTAL];
}
break;
}
} while ((child_index = _next(child_index)) < SIZE_MAX);
}
}
if (post_compute[UI_AXIS_VERTICAL]) {
elm->size.computed_size[UI_AXIS_VERTICAL] = 0;
size_t child_index = elm->first;
if (child_index < SIZE_MAX) {
do {
__auto_type child = _elm(child_index);
switch (elm->size.axis) {
case UI_AXIS_HORIZONTAL:
if (child->size.computed_size[UI_AXIS_VERTICAL] >
elm->size.computed_size[UI_AXIS_VERTICAL]) {
elm->size.computed_size[UI_AXIS_VERTICAL] =
child->size.computed_size[UI_AXIS_VERTICAL];
}
break;
case UI_AXIS_VERTICAL:
elm->size.computed_size[UI_AXIS_VERTICAL] +=
child->size.computed_size[UI_AXIS_VERTICAL];
break;
}
} while ((child_index = _next(child_index)) < SIZE_MAX);
}
}
}
void ui_update_cache(ui_context *cx, size_t element_index) {
if (element_index == SIZE_MAX)
return;
size_t child_index = _elm(element_index)->first;
if (child_index < SIZE_MAX) {
do {
__auto_type child = _elm(child_index);
size_t last_instantiated_index = cx->frame_index;
ui_element_cache_data *cache;
if ((cache = ht_get(&cx->cached_elements, child->key))) {
last_instantiated_index = cache->last_instantiated_index;
}
ht_set(&cx->cached_elements, child->key,
&(ui_element_cache_data){
.label = child->label,
.size =
{
.axis = child->size.axis,
.semantic_size = {child->size.semantic_size[0],
child->size.semantic_size[1]},
.computed_size = {child->size.computed_size[0],
child->size.computed_size[1]},
.computed_pos = {child->size.computed_pos[0],
child->size.computed_pos[1]},
},
.last_instantiated_index = last_instantiated_index,
});
ui_update_cache(cx, child_index);
} while ((child_index = _next(child_index)) < SIZE_MAX);
}
}
typedef void (*_ui_render_text_func)(string text, float position[2]);
typedef void (*_ui_render_rect_func)(float position[2], float size[2],
float color[4]);
void ui_render(ui_context *cx, _ui_render_text_func text_func,
_ui_render_rect_func rect_func) {
for (size_t i = 1; i < cx->frame_elements.size; ++i) {
string text = cx->frame_elements.data[i].key;
ui_element_frame_data *elm = &cx->frame_elements.data[i];
if (_flags(i, UI_FLAG_DRAW_TEXT)) {
text_func(text, (float[]){(float)elm->size.computed_pos[0],
(float)elm->size.computed_pos[1]});
}
if (_flags(i, UI_FLAG_DRAW_BACKGROUND)) {
float c = _ui_test_interaction(cx, i).hovering &&
_flags(i, UI_FLAG_HOVERABLE)
? 0.8
: 0.2;
rect_func((float[]){(float)elm->size.computed_pos[0],
(float)elm->size.computed_pos[1]},
(float[]){(float)elm->size.computed_size[0],
(float)elm->size.computed_size[1]},
(float[]){c, c, c, 1.0});
}
}
}
void ui_prune(ui_context *cx) {
for (size_t i = 0; i < cx->cached_elements.capacity; ++i) {
if (cx->cached_elements.key_slots[i].key.data != NULL) {
string key = cx->cached_elements.key_slots[i].key;
// if this element hasn't been created in the past 5 frames,
// remove it
ui_element_cache_data *cached = ht_get(&cx->cached_elements, key);
if (cached &&
cached->last_instantiated_index < cx->frame_index - 5) {
// fprintf(stderr, "removing %.*s from cache, cache index:
// %zu, frame index: %zu\n", (int)key.len, key.data,
// cached->last_instantiated_index, cx->frame_index);
ht_remove(&cx->cached_elements, key);
}
}
}
size_t child_index = _elm(0)->first;
do {
__auto_type elm = _elm(child_index);
if (elm->label.owned) {
free(elm->label.data);
}
} while ((child_index = _next(child_index)) < SIZE_MAX);
cx->frame_index += 1;
cx->frame_elements.size = 1;
cx->frame_elements.data[0].first = SIZE_MAX;
cx->frame_elements.data[0].prev = SIZE_MAX;
cx->frame_elements.data[0].next = SIZE_MAX;
cx->frame_elements.data[0].last = SIZE_MAX;
cx->frame_elements.data[0].parent = SIZE_MAX;
cx->current_parent = 0;
}
void ui_update_input(ui_context *cx, ui_context_input new_input) {
cx->last_input = cx->input;
cx->input = new_input;
}
#endif
#endif