mch2022-talktopics/components/renze-graphics/driver_framebuffer_window.cpp

/*
 * The functions in this file allow for managing windows
 * windows are framebuffers that can be moved and rendered
 * to the primary framebuffer
 */

#include "include/driver_framebuffer_internal.h"

/* Variables */
Window* windows = NULL;

/* Private functions */
inline Window* _create_window()
{ //Create an empty window object
	Window* window = (Window*) calloc(1, sizeof(Window));
	if (!window) return NULL;
	memset(window, 0, sizeof(Window));
	return window;
}

inline void _add_window(Window* window)
{ //Add a window to the linked list
	if (windows == NULL) {
		windows = window;
		return;
	}
	
	Window* lastWindow = windows;
	while (lastWindow->_nextWindow != NULL) {
		lastWindow = lastWindow->_nextWindow;
	}
	lastWindow->_nextWindow = window;
}

void _debug_windows()
{
	Window* window = windows;
	printf("Windows: ");
	while (window != NULL) {
		printf("%s ", window->name);
		window = window->_nextWindow;
	}
	printf("\n");
}

inline void _remove_window_from_linked_list(Window* window)
{ //Remove a window from the linked list
	Window* prevWindow = window->_prevWindow;
	Window* nextWindow = window->_nextWindow;
	if (prevWindow) prevWindow->_nextWindow = nextWindow; //Link previous to next
	if (nextWindow) nextWindow->_prevWindow = prevWindow; //Link next to previous
	if (windows == window) windows = nextWindow; //Change the start window of the linked list
}

/* Public functions */

Window* driver_framebuffer_window_create(const char* name, uint16_t width, uint16_t height)
{
	if (driver_framebuffer_window_find(name)) return NULL; //If the window already exists do nothing and return.
	Window* window = _create_window();
	
	/* Set properties */
	window->name                   = strdup(name);
	window->width                  = width;
	window->height                 = height;
	window->orientation            = landscape;
	window->enableTransparentColor = false;
	window->transparentColor       = 0xFFFFFF;
	
	/* Configure automatic rendering */
	window->visible                = false;
	window->hOffset                = 0;
	window->vOffset                = 0;
	window->drawWidth              = width;
	window->drawHeight             = height;
	
	/* Buffer */
	window->buffer = (uint8_t*) heap_caps_malloc(((width*height*PIXEL_SIZE)/8)+1, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);

	/* Linked list */
	window->_prevWindow = driver_framebuffer_window_last();
	window->_nextWindow = NULL;
	_add_window(window); //Add window to linked list of windows
	return window;
}

void driver_framebuffer_window_remove(Window* window)
{
	if (window->buffer) free(window->buffer);
	_remove_window_from_linked_list(window);
	free(window);
}

Window* driver_framebuffer_window_find(const char* name)
{
	Window* currentWindow = windows;
	while (currentWindow != NULL) {
		if ((strlen(name) == strlen(currentWindow->name)) &&
			(strcmp(currentWindow->name, name)==0)
		) {
			return currentWindow;
		}
		currentWindow = currentWindow->_nextWindow;
	}
	return NULL;
}

Window* driver_framebuffer_window_first()
{
	return windows;
}

Window* driver_framebuffer_window_next(Window* currentWindow)
{
    if (currentWindow == NULL) return NULL;
    return currentWindow->_nextWindow;
}

Window* driver_framebuffer_window_last()
{
	Window* lastWindow = windows;
	while (lastWindow && lastWindow->_nextWindow != NULL) {
		lastWindow = lastWindow->_nextWindow;
	}
	return lastWindow;
}

bool driver_framebuffer_window_rename(Window* window, const char* newName) {
	if (!window) return false;
	char* newNameBuffer = (char*) malloc(strlen(newName) + 1);
	if (newNameBuffer == NULL) return false;
    memset(newNameBuffer, 0, strlen(newName) + 1);
	strncpy(newNameBuffer, newName, strlen(newName));
	free(window->name);
	window->name = newNameBuffer;
    return true;
}

void driver_framebuffer_window_focus(Window* window)
{
	_remove_window_from_linked_list(window);
	if (windows == window) windows = window->_nextWindow;
	window->_prevWindow = driver_framebuffer_window_last();
	_add_window(window);
	window->_nextWindow = NULL;
}

void driver_framebuffer_window_getSize(Window* window, int16_t* width, int16_t* height)
{
	if (window == NULL) {
		//No window provided, use global context
		*width = FB_WIDTH;
		*height = FB_HEIGHT;
	} else {
		//Window provided, use window context
		*width  = window->width;
		*height = window->height;
	}
}