Move clipping and drawing to base class and fix int<->float warnings.

CMakeLists.txt

@@ -6,7 +6,7 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/include")
 include(TargetArch)
 include(FindPkgConfig)
 
-set(common_gcc_flags "-Wall -Wextra -pedantic")
+set(common_gcc_flags "-Wall -Wextra -pedantic -Wconversion")
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${common_gcc_flags}")
 set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} ${common_gcc_flags}")
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} ${common_gcc_flags}")

src/gamescenebase.cpp

@@ -1,8 +1,13 @@
 #include "gamescenebase.hpp"
 #include "inputbag.hpp"
 #include "sdlmain.hpp"
+#include "rect_to_sdl.hpp"
+#include "rect.hpp"
+#include "texture.hpp"
 #include <cassert>
 #include <SDL2/SDL.h>
+#include <algorithm>
+#include <ciso646>
 
 namespace curry {
 	namespace {
@@ -38,12 +43,56 @@ namespace curry {
 			}
 			return false;
 		}
+
+		///----------------------------------------------------------------------
+		///Adjustes parSrc and parDest so that parDest will fit into parClip and
+		///parSrc to be the relevant part of the source texture to be drawn.
+		///Returns true if such operation was possible and parSrc and parDest
+		///got set to a valid value, otherwise false.
+		///----------------------------------------------------------------------
+		bool clip_rect (Rect<float>& parSrc, Rect<float>& parDest, const Rect<float>& parClip) {
+			typedef Rect<float> RectFloat;
+			assert(parSrc.is_valid());
+			assert(parDest.is_valid());
+
+			//If the dest rect is completely out of the clipping region, there
+			//is nothing to do at all.
+			if (parDest.to <= parClip.from or parDest.from >= parClip.to)
+				return false;
+
+			{
+				const RectFloat clip(vec2f(0.0f), vec2f(1.0f));
+				const vec2f srcWidthHeight(parSrc.width_height());
+				const vec2f scaledOffs((parDest.from - parClip.from) / parClip.width_height());
+				parSrc.from -= vec2f(std::min(0.0f, scaledOffs.x() * srcWidthHeight.x()), std::min(0.0f, scaledOffs.y() * srcWidthHeight.y()));
+				const vec2f scaledCrop((parClip.to - parDest.to) / parClip.width_height());
+				parSrc.to += vec2f(std::min(0.0f, scaledCrop.x() * srcWidthHeight.x()), std::min(0.0f, scaledCrop.y() * srcWidthHeight.y()));
+				assert(parSrc.is_valid());
+			}
+
+			RectFloat dst(parDest.from - parClip.from, parDest.to - parClip.from);
+			dst.from.x() = std::max(dst.from.x(), parClip.from.x());
+			dst.from.y() = std::max(dst.from.y(), parClip.from.y());
+			dst.to.x() = std::min(dst.to.x(), parClip.to.x());
+			dst.to.y() = std::min(dst.to.y(), parClip.to.y());
+
+			if (not dst.is_valid())
+				return false;
+
+			parDest.from += parClip.from;
+			parDest.to += parClip.from;
+
+			assert(parDest.is_valid());
+			return true;
+		}
 	} //unnamed namespace
 
 	GameSceneBase::GameSceneBase (cloonel::SDLMain* parSdlMain) :
 		m_time0(std::chrono::steady_clock::now()),
 		m_input(std::make_unique<cloonel::InputBag>()),
 		m_sdlmain(parSdlMain),
+		m_screen_width(static_cast<float>(m_sdlmain->WidthHeight().x())),
+		m_screen_height(static_cast<float>(m_sdlmain->WidthHeight().y())),
 		m_wants_to_quit(false)
 	{
 		assert(m_sdlmain);
@@ -82,6 +131,7 @@ namespace curry {
 		const float delta = std::chrono::duration<float>(time1 - m_time0).count();
 		m_time0 = time1;
 		this->on_update(delta);
+		SDL_RenderPresent(this->sdl_main()->GetRenderer());
 	}
 
 	cloonel::SDLMain* GameSceneBase::sdl_main() {
@@ -91,4 +141,14 @@ namespace curry {
 	cloonel::InputBag& GameSceneBase::input_bag() {
 		return *m_input;
 	}
+
+	void GameSceneBase::draw_clipped (Texture& parTexture, Rect<float> parSrc, Rect<float> parDest) {
+		const vec2f lefttop(0.0f);
+		const vec2f rightbottom(m_screen_width, m_screen_height);
+		clip_rect(parSrc, parDest, Rect<float>(lefttop, rightbottom));
+
+		auto src = make_sdlrect(parSrc);
+		auto dst = make_sdlrect(parDest);
+		SDL_RenderCopy(m_sdlmain->GetRenderer(), parTexture.texture(), &src, &dst);
+	}
 } //namespace curry

src/gamescenebase.hpp

@@ -9,6 +9,9 @@ namespace cloonel {
 } //namespace cloonel
 
 namespace curry {
+	class Texture;
+	template <typename T> class Rect;
+
 	class GameSceneBase {
 	public:
 		explicit GameSceneBase (cloonel::SDLMain* parSdlMain);
@@ -28,11 +31,14 @@ namespace curry {
 		virtual void on_update (float parDeltaT) = 0;
 		cloonel::SDLMain* sdl_main();
 		cloonel::InputBag& input_bag();
+		void draw_clipped (Texture& parTexture, Rect<float> parSrc, Rect<float> parDest);
 
 	private:
 		std::chrono::time_point<std::chrono::steady_clock> m_time0;
 		std::unique_ptr<cloonel::InputBag> m_input;
 		cloonel::SDLMain* m_sdlmain;
+		float m_screen_width;
+		float m_screen_height;
 		bool m_wants_to_quit;
 	};
 } //namespace curry

src/ingamescene.cpp

@@ -7,6 +7,7 @@
 #include "worldgrid.hpp"
 #include "worldviewport.hpp"
 #include "texture.hpp"
+#include "rect.hpp"
 #include <SDL2/SDL.h>
 #include <algorithm>
 
@@ -18,22 +19,12 @@ namespace curry {
 			ActionRight,
 			ActionDown
 		};
-
-		void clip (SDL_Rect& parSource, SDL_Rect& parDest, const vec2i& parTopLeft, const vec2i& parBotRight) {
-			if (parDest.x < parTopLeft.x()) {
-				const auto diff = parTopLeft.x() - parDest.x;
-				parDest.x = parTopLeft.x();
-				parDest.w -= diff;
-				parSource.x += diff;
-				parSource.w -= diff;
-			}
-		}
 	} //unnamed namespace
 
 	struct IngameScene::LocalData {
 		LocalData (const vec2us& parTileSize, const vec2us& parTileCount, cloonel::SDLMain* parSDLMain) :
 			world(parTileSize, parTileCount),
-			viewport(&world, vec2i(parSDLMain->WidthHeight())),
+			viewport(&world, vec2f(parSDLMain->WidthHeight())),
 			player(parTileSize)
 		{
 		}
@@ -82,18 +73,17 @@ namespace curry {
 		if (cloonel::IsPressed(input_bag(), ActionDown))
 			viewport.set_position(viewport.position() + vec2f(0, speed));
 
-		const auto tilesize(world.tile_size());
+		const auto tilesize(static_cast<vec2f>(world.tile_size()));
 		for (auto tile : viewport) {
-			vec2us idx(tile.index & 1, (tile.index >> 1) & 1);
-			vec2us src_rect_xy = idx * tilesize;
+			vec2f idx(static_cast<float>(tile.index & 1), static_cast<float>((tile.index >> 1) & 1));
+			vec2f src_rect_xy = idx * tilesize;
+			vec2f pixel_pos = vector_cast<vec2f>(tile.pixel_pos);
 
 			//std::cout << "Drawing src " << src_rect_xy << " dst " << tile.pixel_pos << '\n';
-			SDL_Rect src{src_rect_xy.x(), src_rect_xy.y(), tilesize.x(), tilesize.y()};
-			SDL_Rect dst{tile.pixel_pos.x(), tile.pixel_pos.y(), tilesize.x(), tilesize.y()};
-			clip(src, dst, vec2i(0), sdl_main()->WidthHeight());
-			SDL_RenderCopy(this->sdl_main()->GetRenderer(), m_local_data->worldtiles.texture(), &src, &dst);
+			Rect<float> src_rect(src_rect_xy, src_rect_xy + tilesize);
+			Rect<float> dst_rect(pixel_pos, pixel_pos + tilesize);
+			this->draw_clipped(m_local_data->worldtiles, src_rect, dst_rect);
 		}
-		SDL_RenderPresent(this->sdl_main()->GetRenderer());
 	}
 
 	void IngameScene::on_destroy() noexcept {

src/rect.hpp

@@ -0,0 +1,62 @@
+#pragma once
+
+#include "vector.hpp"
+#if !defined(NDEBUG)
+#	include <iostream>
+#endif
+
+namespace curry {
+	template <typename T>
+	class Rect {
+	public:
+		typedef vwr::Vec<std::array<T, 2>> VecType;
+
+		Rect (T parLeft, T parTop, T parRight, T parBottom);
+		template <typename V1, typename V2>
+		Rect (const vwr::Vec<V1>& parLeftTop, const vwr::Vec<V2>& parBottomRight);
+
+		T left() const { return from.x(); }
+		T top() const { return from.y(); }
+		T right() const { return to.x(); }
+		T bottom() const { return to.y(); }
+		T& left() { return from.x(); }
+		T& top() { return from.y(); }
+		T& right() { return to.x(); }
+		T& bottom() { return to.y(); }
+		T width() const { return right() - left(); }
+		T height() const { return bottom() - top(); }
+		VecType width_height() const { return VecType(width(), height()); }
+
+		bool is_valid() const;
+
+		VecType from;
+		VecType to;
+	};
+
+	template <typename T>
+	Rect<T>::Rect (T parLeft, T parTop, T parRight, T parBottom) :
+		from(parLeft, parTop),
+		to(parRight, parBottom)
+	{
+	}
+
+	template <typename T>
+	template <typename V1, typename V2>
+	Rect<T>::Rect (const vwr::Vec<V1>& parLeftTop, const vwr::Vec<V2>& parBottomRight) :
+		Rect(parLeftTop.x(), parLeftTop.y(), parBottomRight.x(), parBottomRight.y())
+	{
+	}
+
+	template <typename T>
+	bool Rect<T>::is_valid() const {
+		return from <= to;
+	}
+
+#if !defined(NDEBUG)
+	template <typename T>
+	std::ostream& operator<< (std::ostream& parStream, const Rect<T>& parRect) {
+		parStream << '{' << parRect.from << '-' << parRect.to << '}';
+		return parStream;
+	}
+#endif
+} //namespace curry

src/rect_to_sdl.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include "rect.hpp"
+#include <SDL2/SDL.h>
+#include <utility>
+
+namespace curry {
+	template <typename T>
+	inline SDL_Rect make_sdlrect (const Rect<T>& parOther) {
+		typedef decltype(std::declval<SDL_Rect>().w) ValueType;
+
+		return SDL_Rect{
+			static_cast<ValueType>(parOther.left()),
+			static_cast<ValueType>(parOther.top()),
+			static_cast<ValueType>(parOther.width()),
+			static_cast<ValueType>(parOther.height())
+		};
+	}
+} //namespace curry

src/worldviewport.cpp

@@ -3,7 +3,7 @@
 #include <cassert>
 
 namespace curry {
-	WorldViewport::WorldViewport (WorldGrid* parWorld, vec2i parSize) :
+	WorldViewport::WorldViewport (WorldGrid* parWorld, vec2f parSize) :
 		m_position(0),
 		m_size(parSize),
 		m_world(parWorld)

src/worldviewport.hpp

@@ -10,7 +10,7 @@ namespace curry {
 	public:
 		typedef TileIterator iterator;
 
-		WorldViewport (WorldGrid* parWorld, vec2i parSize);
+		WorldViewport (WorldGrid* parWorld, vec2f parSize);
 		const WorldGrid* world() const;
 		const vec2f& position() const;
 		const vec2f& size() const;