xlesses/xlesses.c

/*
 * Copyright (c) 2023 : Ognjen 'xolatile' Milan Robovic
 *
 * Xlesses is free software! You will redistribute it or modify it under the terms of the GNU General Public License by Free Software Foundation.
 * And when you do redistribute it or modify it, it will use either version 3 of the License, or (at yours truly opinion) any later version.
 * It is distributed in the hope that it will be useful or harmful, it really depends... But no warranty what so ever, seriously. See GNU/GPLv3.
 */

#ifndef XLESSES_SOURCE
#define XLESSES_SOURCE

#include <xolatile/xlesses.h>

char * blesses_window_title    = "xolatile";
int    blesses_window_width    = 1800;
int    blesses_window_height   = 900;
int    blesses_active          = 1;
int    blesses_cursor_x        = 0;
int    blesses_cursor_y        = 0;
int    blesses_signal          = 0;
int  * blesses_sub_framebuffer = NULL;
int  * blesses_framebuffer     = NULL;

void (* blesses_action [BLESSES_SIGNAL_COUNT]) (void) = { NULL };

xcb_window_t          blesses_window     = 0;
xcb_gcontext_t        blesses_context    = 0;
xcb_pixmap_t          blesses_pixmap     = 0;
xcb_connection_t    * blesses_connection = NULL;
xcb_screen_t        * blesses_screen     = NULL;
xcb_image_t         * blesses_image      = NULL;

void blesses_initialize (void) {
	unsigned int window_flags [2] = {
		0,
		XCB_EVENT_MASK_NO_EVENT        |
		XCB_EVENT_MASK_EXPOSURE        |
		XCB_EVENT_MASK_RESIZE_REDIRECT |
		XCB_EVENT_MASK_KEY_RELEASE     |
		XCB_EVENT_MASK_KEY_PRESS       |
		XCB_EVENT_MASK_BUTTON_RELEASE  |
		XCB_EVENT_MASK_BUTTON_PRESS
	};

	unsigned short int window_width  = (unsigned short int) blesses_window_width;
	unsigned short int window_height = (unsigned short int) blesses_window_height;

	blesses_connection = xcb_connect (NULL, NULL);

	log_in (LOG_FAILURE, blesses_connection == NULL, "blesses : blesses_initialize : XCB connection is null pointer.");

	blesses_screen = xcb_setup_roots_iterator (xcb_get_setup (blesses_connection)).data;

	blesses_window  = xcb_generate_id (blesses_connection);
	blesses_context = xcb_generate_id (blesses_connection);
	blesses_pixmap  = xcb_generate_id (blesses_connection);

	window_flags [0] = blesses_screen->black_pixel;

	xcb_create_window (blesses_connection, blesses_screen->root_depth, blesses_window, blesses_screen->root, 0, 0, window_width, window_height, 10, XCB_WINDOW_CLASS_INPUT_OUTPUT,
	                   blesses_screen->root_visual, XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK, window_flags);

	xcb_map_window (blesses_connection, blesses_window);

	xcb_change_property (blesses_connection, XCB_PROP_MODE_REPLACE, blesses_window, XCB_ATOM_WM_NAME, XCB_ATOM_STRING, 8, string_length (blesses_window_title), blesses_window_title);

	xcb_create_pixmap (blesses_connection, blesses_screen->root_depth, blesses_pixmap, blesses_window, window_width, window_height);

	xcb_create_gc (blesses_connection, blesses_context, blesses_pixmap, 0, NULL);

	xcb_flush (blesses_connection);

	blesses_sub_framebuffer = allocate (blesses_window_width * blesses_window_height * (int) sizeof (* blesses_sub_framebuffer) / 4);
	blesses_framebuffer     = allocate (blesses_window_width * blesses_window_height * (int) sizeof (* blesses_framebuffer));

	log_out ();
}

void blesses_deinitialize (void) {
	blesses_sub_framebuffer = deallocate (blesses_sub_framebuffer);
	blesses_framebuffer     = deallocate (blesses_framebuffer);

	xcb_free_gc (blesses_connection, blesses_context);

	xcb_free_pixmap (blesses_connection, blesses_pixmap);

	xcb_destroy_window (blesses_connection, blesses_window);

	xcb_disconnect (blesses_connection);
}

void blesses_synchronize (void) {
	int i = 0;
	int j = 0;

	xcb_generic_event_t * generic_event = NULL;

	for (i = 0; i != blesses_window_width * blesses_window_height; i++) {
		blesses_framebuffer [i] = blesses_sub_framebuffer [((i / blesses_window_width) / 2) * (blesses_window_width / 2) + (i % blesses_window_width) / 2];
	}

	blesses_sub_framebuffer = deallocate (blesses_sub_framebuffer);

	blesses_image = xcb_image_create_native (blesses_connection, blesses_window_width, blesses_window_height, XCB_IMAGE_FORMAT_Z_PIXMAP, blesses_screen->root_depth,
	                                         blesses_framebuffer, (unsigned int) (blesses_window_width * blesses_window_height * (int) sizeof (* blesses_framebuffer)),
	                                         (unsigned char *) blesses_framebuffer);

	xcb_image_put (blesses_connection, blesses_pixmap, blesses_context, blesses_image, 0, 0, 0);

	xcb_image_destroy (blesses_image);

	xcb_copy_area (blesses_connection, blesses_pixmap, blesses_window, blesses_context, 0, 0, 0, 0, blesses_window_width, blesses_window_height);

	blesses_framebuffer = NULL;

	generic_event = xcb_wait_for_event (blesses_connection);

	switch (generic_event->response_type & 127) {
		case XCB_EXPOSE: {
			xcb_flush (blesses_connection);
		} break;
		case XCB_KEY_PRESS: {
			blesses_signal = (int) ((xcb_key_press_event_t *) generic_event)->detail;
			if (blesses_signal == 24) {
				blesses_active = 0;
			}
		} break;
		default: {
		} break;
	}

	generic_event = deallocate (generic_event);

	if ((blesses_sub_framebuffer == NULL) && (blesses_framebuffer == NULL)) {
		blesses_sub_framebuffer = allocate (blesses_window_width * blesses_window_height * (int) sizeof (* blesses_sub_framebuffer) / 4);
		blesses_framebuffer     = allocate (blesses_window_width * blesses_window_height * (int) sizeof (* blesses_framebuffer));
	}

	log_out ();
}

void blesses_render_background_colour (int colour) {
	int x, y;

	for (y = 0; y != blesses_window_height / 2; ++y) {
		for (x = 0; x != blesses_window_width / 2; ++x) {
			blesses_sub_framebuffer [y * (blesses_window_width / 2) + x] = 0XFF000000 | colour;
		}
	}
}

void blesses_render_character (char character, int x, int y, int foreground, int background) {
	const unsigned long int font_code ['~' - ' ' + 1] = {
		0X0000000000000000, 0X00180018183C3C18, 0X0000000000363636, 0X006C6CFE6CFE6C6C, 0X00187ED07C16FC30, 0X0060660C18306606, 0X00DC66B61C36361C, 0X0000000000181818,
		0X0030180C0C0C1830, 0X000C18303030180C, 0X0000187E3C7E1800, 0X000018187E181800, 0X0C18180000000000, 0X000000007E000000, 0X0018180000000000, 0X0000060C18306000,
		0X003C666E7E76663C, 0X007E181818181C18, 0X007E0C183060663C, 0X003C66603860663C, 0X0030307E363C3830, 0X003C6660603E067E, 0X003C66663E060C38, 0X000C0C0C1830607E,
		0X003C66663C66663C, 0X001C30607C66663C, 0X0018180018180000, 0X0C18180018180000, 0X0030180C060C1830, 0X0000007E007E0000, 0X000C18306030180C, 0X001800181830663C,
		0X003C06765676663C, 0X006666667E66663C, 0X003E66663E66663E, 0X003C66060606663C, 0X001E36666666361E, 0X007E06063E06067E, 0X000606063E06067E, 0X003C66667606663C,
		0X006666667E666666, 0X007E18181818187E, 0X001C36303030307C, 0X0066361E0E1E3666, 0X007E060606060606, 0X00C6C6D6D6FEEEC6, 0X006666767E6E6666, 0X003C66666666663C,
		0X000606063E66663E, 0X006C36566666663C, 0X006666363E66663E, 0X003C66603C06663C, 0X001818181818187E, 0X003C666666666666, 0X00183C6666666666, 0X00C6EEFED6D6C6C6,
		0X0066663C183C6666, 0X001818183C666666, 0X007E060C1830607E, 0X003E06060606063E, 0X00006030180C0600, 0X007C60606060607C, 0X000000000000663C, 0XFFFF000000000000,
		0X000000000030180C, 0X007C667C603C0000, 0X003E6666663E0606, 0X003C6606663C0000, 0X007C6666667C6060, 0X003C067E663C0000, 0X000C0C0C3E0C0C38, 0X3C607C66667C0000,
		0X00666666663E0606, 0X003C1818181C0018, 0X0E181818181C0018, 0X0066361E36660606, 0X003C18181818181C, 0X00C6D6D6FE6C0000, 0X00666666663E0000, 0X003C6666663C0000,
		0X06063E66663E0000, 0XE0607C66667C0000, 0X000606066E360000, 0X003E603C067C0000, 0X00380C0C0C3E0C0C, 0X007C666666660000, 0X00183C6666660000, 0X006CFED6D6C60000,
		0X00663C183C660000, 0X3C607C6666660000, 0X007E0C18307E0000, 0X003018180E181830, 0X0018181818181818, 0X000C18187018180C, 0X000000000062D68C, 0X0000000000000000
	};

	int offset;

	if ((x <= -1) || (x >= blesses_window_width  / 2 - BLESSES_FONT_WIDTH))  return;
	if ((y <= -1) || (y >= blesses_window_height / 2 - BLESSES_FONT_HEIGHT)) return;

	log_in (LOG_WARNING, blesses_sub_framebuffer == NULL,                  "blesses : render_character : Sub framebuffer was not allocated.");
	log_in (LOG_WARNING, blesses_framebuffer     == NULL,                  "blesses : render_character : Framebuffer was not allocated.");
	log_in (LOG_WARNING, character_is_invisible (character),               "blesses : render_character : Character is not in visible ASCII range.");
	log_in (LOG_WARNING, x <= -1,                                          "blesses : render_character : X position is under lower limit.");
	log_in (LOG_WARNING, y <= -1,                                          "blesses : render_character : Y position is under lower limit.");
	log_in (LOG_WARNING, x >= blesses_window_width  - BLESSES_FONT_WIDTH,  "blesses : render_character : X position is above upper limit.");
	log_in (LOG_WARNING, y >= blesses_window_height - BLESSES_FONT_HEIGHT, "blesses : render_character : Y position is above upper limit.");

	for (offset = 0; offset != BLESSES_FONT_WIDTH * BLESSES_FONT_HEIGHT; ++offset) {
		int u = offset / BLESSES_FONT_WIDTH + y;
		int v = offset % BLESSES_FONT_WIDTH + x;

		blesses_sub_framebuffer [u * (blesses_window_width / 2) + v] = ((font_code [(int) (character - ' ')] >> offset) % 2) ? foreground : background;
	}

	log_out ();
}

void blesses_render_string_limit (char * string, int limit, int * x, int * y, int foreground, int background) {
	int offset;

	for (offset = 0; offset != limit; ++offset) {
		if (string [offset] == '\t') {
			* x += BLESSES_FONT_WIDTH * BLESSES_FONT_TABULATOR;
		} else if (string [offset] == '\n') {
			* y += BLESSES_FONT_HEIGHT;
			* x *= 0;
		} else {
			blesses_render_character (string [offset], * x, * y, foreground, background);

			* x += BLESSES_FONT_WIDTH;
		}
	}
}

void blesses_render_string (char * string, int * x, int * y, int foreground, int background) {
	blesses_render_string_limit (string, string_length (string), x, y, foreground, background);
}

#endif