trmnl_sdl/Widgets/WidgetRect.cpp

#include "WidgetRect.h"

#include <vector>

#include "../sdl_helpers.h"

using std::vector;

WidgetRect::WidgetRect(int x, int y, int width, int height,
	int radius, int stroke_size, SDL_Color color)
: Widget(x, y, width, height),
m_color(color),
m_stroke_size(stroke_size),
m_radius(radius)
{
}

WidgetRect::WidgetRect(int x, int y, int width, int height,
		int radius, int stroke_size)
: Widget(x, y, width, height),
m_color{.r = 0, .g = 0, .b = 0, .a = SDL_ALPHA_OPAQUE},
m_stroke_size(stroke_size),
m_radius(radius)
{
}

void WidgetRect::draw()
{
	if (nullptr == m_surface)
	{
		return;
	}

	// Clear surface
	SDL_FillRect(m_surface, nullptr, SDL_MapRGBA(m_surface->format, 255, 255, 255, SDL_ALPHA_TRANSPARENT));

	if (m_radius > 0)
	{
		// Draw rounded corners here
		draw_circle_corner(m_rect.w - m_radius, m_radius - 1, 1);
		draw_circle_corner(m_radius - 1, m_radius - 1, 2);
		draw_circle_corner(m_radius - 1, m_rect.h - m_radius, 3);
		draw_circle_corner(m_rect.w - m_radius, m_rect.h - m_radius, 4);

		// Draw X rect
		if (m_radius * 2 < m_rect.w)
		{
			SDL_Rect rect;
			rect.x = 0;
			rect.y = m_radius;
			rect.w = m_rect.w;
			rect.h = m_rect.h - 2 * m_radius;
			SDL_FillRect(m_surface, &rect, SDL_MapRGBA(m_surface->format, m_color.r, m_color.g, m_color.b, m_color.a));

			if (m_stroke_size > 0)
			{
				rect.x = m_stroke_size;
				rect.y = m_radius;
				rect.w = m_rect.w - 2 * m_stroke_size;
				rect.h = m_rect.h - 2 * m_radius;
				SDL_FillRect(m_surface, &rect, SDL_MapRGBA(m_surface->format, 255, 255, 255, SDL_ALPHA_TRANSPARENT));
			}
		}

		// Draw Y rect
		if (m_radius * 2 < m_rect.h)
		{
			SDL_Rect rect;
			rect.x = m_radius;
			rect.y = 0;
			rect.w = m_rect.w - 2 * m_radius;
			rect.h = m_rect.h;
			SDL_FillRect(m_surface, &rect, SDL_MapRGBA(m_surface->format, m_color.r, m_color.g, m_color.b, m_color.a));

			if (m_stroke_size > 0)
			{
				rect.x = m_radius;
				rect.y = m_stroke_size;
				rect.w = m_rect.w - 2 * m_radius;
				rect.h = m_rect.h - 2 * m_stroke_size;
				SDL_FillRect(m_surface, &rect, SDL_MapRGBA(m_surface->format, 255, 255, 255, SDL_ALPHA_TRANSPARENT));
			}
		}
	}
	else
	{
		SDL_Rect rect;
		rect.x = 0;
		rect.y = 0;
		rect.w = m_rect.w;
		rect.h = m_rect.h;
		SDL_FillRect(m_surface, &rect, SDL_MapRGBA(m_surface->format, m_color.r, m_color.g, m_color.b, m_color.a));

		if (m_stroke_size > 0)
		{
			rect.x = m_stroke_size;
			rect.y = m_stroke_size;
			rect.w = m_rect.w - 2 * m_stroke_size;
			rect.h = m_rect.h - 2 * m_stroke_size;
			SDL_FillRect(m_surface, &rect, SDL_MapRGBA(m_surface->format, 255, 255, 255, SDL_ALPHA_TRANSPARENT));
		}
	}
}

std::unique_ptr<Widget> WidgetRect::builder(const nlohmann::json& j)
{
	int x = 0;
	int y = 0;
	int width = 0;
	int height = 0;
	int radius = 0;
	int stroke_size = -1;
	SDL_Color color = {.r = 0, .g = 0, .b = 0, .a = SDL_ALPHA_OPAQUE};

	json_extract(j, "x", x);
	json_extract(j, "y", y);
	json_extract(j, "width", width);
	json_extract(j, "height", height);
	json_extract(j, "radius", radius);
	json_extract(j, "stroke", stroke_size);
	json_extract(j, "color", color);

	return std::make_unique<WidgetRect>(x, y, width, height, radius, stroke_size, color);
}

void WidgetRect::draw_circle_corner(int x, int y, int quadrant)
{
	if (0 == m_radius)
	{
		return;
	}

	int x_add;
	int y_add;

	switch (quadrant)
	{
	case 1:
		x_add = 1;
		y_add = -1;
		break;

	case 2:
		x_add = -1;
		y_add = -1;
		break;

	case 3:
		x_add = -1;
		y_add = 1;
		break;

	case 4:
		x_add = 1;
		y_add = 1;
		break;

	default:
		// TODO: Message printing
		return;
		break;
	}

	// Create renderer
	SDL_Renderer* renderer = SDL_CreateSoftwareRenderer(m_surface);
	if (nullptr == renderer)
	{
		// TODO: Message printing
		return;
	}
	SDL_SetRenderDrawColor(renderer, m_color.r, m_color.g, m_color.b, m_color.a);

	vector<SDL_Point> points;

	int max_dist = m_radius * m_radius;
	int min_dist = 0;
	if (m_stroke_size > 0)
	{
		min_dist = (m_radius - m_stroke_size) * (m_radius - m_stroke_size);
	}

	for (int i_x = 0; i_x < m_radius; ++i_x)
	for (int i_y = 0; i_y < m_radius; ++i_y)
	{
		bool should_fill = false;

		// a2 + b2 = c2
		int dist = i_x * i_x + i_y * i_y;

		// <= c2 (max) && > c2 (min)
		if ((dist <= max_dist) && (dist >= min_dist))
		{
			should_fill = true;
		}

		if (should_fill)
		{
			SDL_Point point =
			{
				.x = x + x_add * i_x,
				.y = y + y_add * i_y
			};

			points.push_back(point);
		}
	}
	SDL_RenderDrawPoints(renderer, points.data(), points.size());
	SDL_DestroyRenderer(renderer);
}