Fixed 'scale to fit' functionality of WidgetImage

Makefile

@@ -2,8 +2,9 @@ src_files += main.cpp
 src_files += sdl_helpers.cpp
 
 src_files += Widgets/Widget.cpp
-src_files += Widgets/WidgetText.cpp
+src_files += Widgets/WidgetImage.cpp
 src_files += Widgets/WidgetRect.cpp
+src_files += Widgets/WidgetText.cpp
 
 all:
 	g++ $(src_files) -Wall -lSDL2 -lSDL2_ttf -lSDL2_image -o trmnl_sdl

Widgets/WidgetImage.cpp

@@ -0,0 +1,128 @@
+#include "WidgetImage.h"
+
+#include <SDL2/SDL_image.h>
+
+using std::string;
+
+WidgetImage::WidgetImage(int x, int y, int width, int height, string filename,
+	ImageResize resize_type, HorizontalAlign halign, VerticalAlign valign,
+	SDL_Color bg_color)
+: Widget(x, y, width, height),
+m_filename(filename),
+m_image_surface(nullptr),
+m_resize_type(resize_type),
+m_halign(halign),
+m_valign(valign),
+m_bg_color(bg_color)
+{
+	m_image_surface = IMG_Load(m_filename.c_str());
+	if (nullptr == m_image_surface)
+	{
+		// TODO: Print errors
+	}
+}
+
+void WidgetImage::draw()
+{
+	if (nullptr == m_surface)
+	{
+		return;
+	}
+
+	// Clear surface with BG color
+	SDL_FillRect(m_surface, nullptr,
+		SDL_MapRGBA(m_surface->format, m_bg_color.r, m_bg_color.g, m_bg_color.b, m_bg_color.a));
+
+	if (nullptr == m_image_surface)
+	{
+		return;
+	}
+
+	SDL_Rect align;
+	SDL_Surface* scaled_image = nullptr;
+	switch (m_resize_type)
+	{
+	case RESIZE_NONE:
+		align = surface_align(m_surface, m_image_surface, m_halign, m_valign);
+		SDL_BlitSurface(m_image_surface, nullptr, m_surface, &align);
+		break;
+
+	case RESIZE_FIT:
+		scaled_image = image_scale_fit();
+		if (nullptr != scaled_image)
+		{
+			align = surface_align(m_surface, scaled_image, m_halign, m_valign);
+			SDL_BlitScaled(scaled_image, nullptr, m_surface, &align);
+			SDL_FreeSurface(scaled_image);
+		}
+		break;
+
+	case RESIZE_STRETCH:
+		SDL_BlitScaled(m_image_surface, nullptr, m_surface, nullptr);
+		break;
+	}
+}
+
+std::unique_ptr<Widget> WidgetImage::builder(const nlohmann::json& j)
+{
+	int x = 0;
+	int y = 0;
+	int width = 0;
+	int height = 0;
+	string filename;
+	ImageResize resize_type = RESIZE_FIT;
+	HorizontalAlign halign = HALIGN_CENTER;
+	VerticalAlign valign = VALIGN_CENTER;
+	SDL_Color bg_color = {.r = 255, .g = 255, .b = 255, .a = SDL_ALPHA_TRANSPARENT};
+
+	json_extract(j, "x", x);
+	json_extract(j, "y", y);
+	json_extract(j, "width", width);
+	json_extract(j, "height", height);
+	json_extract(j, "filename", filename);
+	json_extract(j, "resize_type", resize_type);
+	json_extract(j, "halign", halign);
+	json_extract(j, "valign", valign);
+	json_extract(j, "bg_color", bg_color);
+
+	return std::make_unique<WidgetImage>(x, y, width, height, filename,
+		resize_type, halign, valign, bg_color);
+}
+
+SDL_Surface* WidgetImage::image_scale_fit()
+{
+	SDL_Rect align = {.x = 0, .y = 0, .w = 0, .h = 0};
+
+	if ((nullptr == m_surface) || (nullptr == m_image_surface))
+	{
+		return nullptr;
+	}
+
+	double x_scale = m_surface->w;
+	x_scale /= m_image_surface->w;
+
+	double y_scale = m_surface->h;
+	y_scale /= m_image_surface->h;
+
+	// Find smallest scale factor
+	double min_scale = x_scale;
+	if (y_scale < min_scale)
+	{
+		min_scale = y_scale;
+	}
+
+	// Scale with double in the front and then clamp to int via SDL_Rect
+	align.w = min_scale * m_image_surface->w;
+	align.h = min_scale * m_image_surface->h;
+
+	SDL_Surface* scaled_image_surface =
+		SDL_CreateRGBSurfaceWithFormat(0, align.w, align.h, 32, SDL_PIXELFORMAT_RGBA8888);
+	if (nullptr == scaled_image_surface)
+	{
+		// TODO: Print Error
+		return nullptr;
+	}
+
+	SDL_BlitScaled(m_image_surface, nullptr, scaled_image_surface, nullptr);
+	return scaled_image_surface;
+}

Widgets/WidgetImage.h

@@ -0,0 +1,52 @@
+#ifndef WIDGET_IMAGE_H_
+#define WIDGET_IMAGE_H_
+
+#include "Widget.h"
+
+#include <string>
+
+#include "../sdl_helpers.h"
+
+class WidgetImage : public Widget
+{
+protected:
+	// Image filepath
+	std::string m_filename;
+
+	// Image surface
+	SDL_Surface* m_image_surface;
+
+	// Whether to resize the image and how
+	// RESIZE_NONE - Do not resize
+	// RESIZE_FIT - Scale the image to fit the rectangle
+	// RESIZE_STRETCH - Scale and stretch the image to fit the box perfectly
+	ImageResize m_resize_type;
+
+	// Default - center
+	HorizontalAlign m_halign;
+
+	// Default - center
+	VerticalAlign m_valign;
+
+	// Background color to be used
+	// Default - transparent white
+	SDL_Color m_bg_color;
+
+public:
+	WidgetImage(int x, int y, int width, int height, std::string filename,
+		ImageResize resize_type = RESIZE_FIT,
+		HorizontalAlign halign = HALIGN_CENTER,
+		VerticalAlign valign = VALIGN_CENTER,
+		SDL_Color bg_color = SDL_Color{.r = 255, .g = 255, .b = 255, .a = SDL_ALPHA_TRANSPARENT});
+
+	virtual void draw() override;
+
+	static std::unique_ptr<Widget> builder(const nlohmann::json& j);
+
+protected:
+	// Create a new surface of the image_surface that is scaled via RESIZE_FIT method
+	// NOTE: The user MUST free the surface when done with it
+	SDL_Surface* image_scale_fit();
+};
+
+#endif // WIDGET_IMAGE_H_

Widgets/WidgetRect.cpp

@@ -26,6 +26,11 @@ 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));
 

Widgets/WidgetRect.h

@@ -31,7 +31,7 @@ public:
 
 	static std::unique_ptr<Widget> builder(const nlohmann::json& j);
 
-private:
+protected:
 	// x, y - center of circle
 	// quadrant - 1--4
 	void draw_circle_corner(int x, int y, int quadrant);

Widgets/WidgetText.cpp

@@ -170,6 +170,11 @@ void WidgetText::set_color(SDL_Color text_color)
 
 void WidgetText::draw()
 {
+	if (nullptr == m_surface)
+	{
+		return;
+	}
+
 	// Clear surface
 	SDL_FillRect(m_surface, nullptr, SDL_MapRGBA(m_surface->format, 255, 255, 255, SDL_ALPHA_TRANSPARENT));
 

Widgets/WidgetText.h

@@ -2,7 +2,6 @@
 #define WIDGET_TEXT_H_
 
 #include "Widget.h"
-#include <SDL2/SDL.h>
 
 #include <string>
 

main.cpp

@@ -12,8 +12,9 @@
 
 #include "sdl_helpers.h"
 #include "Widgets/Widget.h"
-#include "Widgets/WidgetText.h"
+#include "Widgets/WidgetImage.h"
 #include "Widgets/WidgetRect.h"
+#include "Widgets/WidgetText.h"
 
 using std::cout;
 using std::endl;
@@ -26,6 +27,7 @@ using nlohmann::json;
 
 void init_builders(map<string, unique_ptr<Widget>(*)(const json&)>& widget_builders)
 {
+	widget_builders["image"] = &WidgetImage::builder;
 	widget_builders["rect"] = &WidgetRect::builder;
 	widget_builders["text"] = &WidgetText::builder;
 }

sdl_helpers.cpp

@@ -87,6 +87,10 @@ SDL_Rect surface_align(const SDL_Surface* base, const SDL_Surface* applied,
 		return align;
 	}
 
+	// These are set in order to handle scaled blits
+	align.w = applied->w;
+	align.h = applied->h;
+
 	if (nullptr == hint_external)
 	{
 		hint = SDL_Rect{.x = 0, .y = 0, .w = applied->w, .h = applied->h};
@@ -167,7 +171,7 @@ void json_extract(const json& j, const string& key, string& out)
 	}
 }
 
-void json_extract(const nlohmann::json& j, const string& key, int& out)
+void json_extract(const json& j, const string& key, int& out)
 {
 	if (j.contains(key) && j[key].is_number_integer())
 	{
@@ -175,7 +179,7 @@ void json_extract(const nlohmann::json& j, const string& key, int& out)
 	}
 }
 
-void json_extract(const nlohmann::json& j, const string& key, bool& out)
+void json_extract(const json& j, const string& key, bool& out)
 {
 	if (j.contains(key) && j[key].is_boolean())
 	{
@@ -238,10 +242,24 @@ void json_extract(const json& j, const string& key, SDL_Color& out)
 	}
 }
 
-void json_extract(const nlohmann::json& j, const string& key, Uint8& out)
+void json_extract(const json& j, const string& key, Uint8& out)
 {
 	if (j.contains(key) && j[key].is_number_unsigned())
 	{
 		out = j[key];
 	}
 }
+
+void json_extract(const json& j, const string& key, ImageResize& out)
+{
+	if (j.contains(key))
+	{
+		try
+		{
+			out = j[key].get<ImageResize>();
+		}
+		catch(const std::exception& e)
+		{
+		}
+	}
+}

sdl_helpers.h

@@ -52,6 +52,20 @@ NLOHMANN_JSON_SERIALIZE_ENUM(TextFit,
 	{FIT_AUTO, "auto"},
 })
 
+enum ImageResize
+{
+	RESIZE_NONE,
+	RESIZE_FIT,
+	RESIZE_STRETCH
+};
+
+NLOHMANN_JSON_SERIALIZE_ENUM(ImageResize,
+{
+	{RESIZE_NONE, "none"},
+	{RESIZE_FIT, "fit"},
+	{RESIZE_STRETCH, "stretch"},
+})
+
 // Call this before everything
 // Prints its messages
 bool init_sdl();
@@ -86,5 +100,6 @@ void json_extract(const nlohmann::json& j, const std::string& key, VerticalAlign
 void json_extract(const nlohmann::json& j, const std::string& key, TextFit& out);
 void json_extract(const nlohmann::json& j, const std::string& key, SDL_Color& out);
 void json_extract(const nlohmann::json& j, const std::string& key, Uint8& out);
+void json_extract(const nlohmann::json& j, const std::string& key, ImageResize& out);
 
 #endif // SDL_HELPERS_H_