vxKernel/src/display/text/render/dtext.c

#include <vhex/display/types.h>
#include <vhex/display/stack.h>
#include <vhex/display/font.h>
#include <vhex/display/text.h>
#include <vhex/display.h>

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


/* internal text information/cache */
struct {
	struct {
		struct {
			char *raw;
			size_t size;
		} *text;
		int number;
		int idx;
	} pool;
} dtext_info = {
	.pool = {
		.text = NULL,
		.number = 0,
		.idx = 0
	}
};

//---
// Internal module functions
//---

VCONSTRUCTOR static void __dtext_constructor(void)
{
	dtext_info.pool.number = 16;
	dtext_info.pool.idx = -1;
	dtext_info.pool.text = calloc(
		dtext_info.pool.number,
		sizeof(*dtext_info.pool.text)
	);
	for (int i = 0; i < dtext_info.pool.number; ++i) {
		dtext_info.pool.text[i].raw = malloc(32);
		dtext_info.pool.text[i].size = 32;
	}
}

VDESTRUCTOR void __dtext_destructor(void)
{
	for (int i = 0; i < dtext_info.pool.number; ++i)
		free(dtext_info.pool.text[i].raw);
	free(dtext_info.pool.text);
}

static void __dtext_quit(void)
{
	dtext_info.pool.idx = -1;
}

//---
// Private functions
//---

/* dtext_info_register() : duplicate the string */
static char *dtext_info_register(char const * const str)
{
	size_t len;

	dtext_info.pool.idx += 1;
	if (dtext_info.pool.idx >= dtext_info.pool.number) {
		dtext_info.pool.number += dtext_info.pool.number;
		dtext_info.pool.text = reallocarray(
			dtext_info.pool.text,
			dtext_info.pool.number,
			sizeof(*dtext_info.pool.text)
		);
		for (int i = dtext_info.pool.idx; i < dtext_info.pool.number; ++i) {
			dtext_info.pool.text[i].raw = malloc(32);
			dtext_info.pool.text[i].size = 32;
		}
	}

	len = strlen(str) + 1;
	if (len >= dtext_info.pool.text[dtext_info.pool.idx].size) {
		dtext_info.pool.text[dtext_info.pool.idx].size = len;
		dtext_info.pool.text[dtext_info.pool.idx].raw = reallocarray(
			dtext_info.pool.text[dtext_info.pool.idx].raw,
			dtext_info.pool.text[dtext_info.pool.idx].size,
			sizeof(char)
		);
	}

	strcpy(dtext_info.pool.text[dtext_info.pool.idx].raw, str);
	return dtext_info.pool.text[dtext_info.pool.idx].raw;
}

//---
// Dstack API
//---

/* dfont_render() : draw caracter in surface */
void dtext_dstack(dsurface_t *surface, uintptr_t *arg)
{
	uint32_t code_point;
	uint8_t const * str;
	font_t *font;
	int glyph_idx;
	int glyph_width;
	int counter;
	int sx;
	int sy;

	/* check culling */
	if (((int)arg[3] < surface->y1 && (int)arg[1] > surface->y2)
		|| ((int)arg[2] < surface->x1 && (int)arg[0] > surface->x2)) {
		return;
	}

	/* draw algo (update me) */
	sx = arg[0];
	sy = arg[1];
	counter = -1;
	font = dfont_get();
	str = (void*)arg[6];
	while (++counter < (int)arg[7])
	{
		code_point = dfont_utf8_next(&str);
		if (code_point == '\n') {
			arg[1] += font->glyph.height;
			arg[0] = sx;
			continue;
		}

		glyph_idx = dfont_glyph_index(font, code_point);
		glyph_width = font->glyph.mono.width;
		if (font->shape.prop == 1)
			glyph_width = font->glyph.prop[glyph_idx].width;

		dfont_char_render(surface, glyph_idx, arg);

		arg[0] += glyph_width + font->char_spacing;

	}
	arg[1] = sy;
	arg[0] = sx;
}

//---
// Public API
//---

/* dtext_opt(): Display a string of text */
did_t dtext_opt(
	int x, int y,
	int fg, int bg,
	int align,
	char const * const str, int size
) {
	size_t width;
	size_t height;
	void *real_str;

	/* get text geometry and handle obvious culling */
	if (dtext_geometry(str, &size, &width, &height) != 0)
		return (-1);
	if (x >= (int)dwidth()
			|| y >= (int)dheight()
			|| x + (int)width < 0
			|| y + (int)height < 0) {
		return (-1);
	}

	/* handle position */
	if (align & DTEXT_CENTER) x = x - (width / 2);
	if (align & DTEXT_RIGHT)  x = x - (width);
	if (align & DTEXT_MIDDLE) y = y - (height / 2);
	if (align & DTEXT_BOTTOM) y = y - (height);

	/* register the string */
	real_str = dtext_info_register(str);

	/* request draw call */
	return dstack_add_action(
		DSTACK_CALL(
			&dtext_dstack,
			x, y, x + width, y + height,
			fg, bg,
			(uintptr_t)real_str, size,
		),
		NULL,
		(dtext_info.pool.idx == 0) ? (void*)&__dtext_quit : NULL
	);
}

/* dtext() : display text information */
did_t dtext(int x, int y, int fg, char const * const text)
{
	return (dtext_opt(x, y, fg, C_NONE, DTEXT_LEFT | DTEXT_TOP, text, -1));
}