From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Sun, 19 Jan 2014 13:47:43 +0000 (+0100)
Subject: speed up rendering by caching world texture
X-Git-Url: http://git.localhorst.tv/?p=gworm.git;a=commitdiff_plain

speed up rendering by caching world texture
---

diff --git a/src/app/Application.cpp b/src/app/Application.cpp
index b7983aa..490e167 100644
--- a/src/app/Application.cpp
+++ b/src/app/Application.cpp
@@ -16,6 +16,7 @@ namespace gworm {
 Application::Application(Canvas &c, World &w)
 : canvas(c)
 , world(w)
+, worldTex(canvas.CreateStaticTexture(world.Size()))
 , focus(Vector<float>(250, 250), 25)
 , cam(c.Size(), focus.Pos())
 , last(SDL_GetTicks())
@@ -158,39 +159,13 @@ void Application::RenderBackground() {
 }
 
 void Application::RenderWorld() {
-	Vector<int> begin(0, 0);
-	Vector<int> end(world.Size());
-	Vector<int> topLeft = cam.ToScreen(Vector<float>(begin));
-	Vector<int> bottomRight = cam.ToScreen(Vector<float>(end));
-	Vector<int> clip(canvas.Size());
-
-	if (begin.x > clip.x || begin.y > clip.y || end.x < 0 || end.y < 0) {
-		return;
+	if (world.ColorDirty()) {
+		worldTex.SetColors(world.GetColors());
+		world.CleanColor();
 	}
 
-	if (topLeft.x < 0) {
-		begin.x -= topLeft.x;
-		topLeft.x = 0;
-	}
-	if (topLeft.y < 0) {
-		begin.y -= topLeft.y;
-		topLeft.y = 0;
-	}
-	if (bottomRight.x > clip.x) {
-		end.x -= bottomRight.x - clip.x;
-		bottomRight.x = clip.x;
-	}
-	if (bottomRight.y > clip.y) {
-		end.y -= bottomRight.y - clip.y;
-		bottomRight.y = clip.y;
-	}
-
-	for (Vector<int> pos(begin), cur(topLeft); pos.y < end.y; ++pos.y, ++cur.y) {
-		for (pos.x = begin.x, cur.x = topLeft.x; pos.x < end.x; ++pos.x, ++cur.x) {
-			canvas.SetColor(world.ColorAt(pos));
-			canvas.Dot(cur);
-		}
-	}
+	const Vector<int> pos = cam.ToScreen(Vector<float>(0, 0));
+	canvas.Copy(worldTex, pos);
 }
 
 void Application::RenderEntities() {
diff --git a/src/app/Application.h b/src/app/Application.h
index 23815d3..5b46f9c 100644
--- a/src/app/Application.h
+++ b/src/app/Application.h
@@ -3,6 +3,7 @@
 
 #include "../graphics/Camera.h"
 #include "../graphics/Moveable.h"
+#include "../graphics/Texture.h"
 #include "../graphics/Vector.h"
 
 #include <SDL.h>
@@ -40,6 +41,8 @@ private:
 	Canvas &canvas;
 	World &world;
 
+	Texture worldTex;
+
 	Moveable<float> focus;
 	Camera cam;
 
diff --git a/src/world/World.cpp b/src/world/World.cpp
index dcac95e..4cb8ffd 100644
--- a/src/world/World.cpp
+++ b/src/world/World.cpp
@@ -9,7 +9,8 @@ World::World(Vector<int> size)
 : size(size)
 , count(size.x * size.y)
 , masses(count, 1000000000.0f)
-, colors(count, Color(0x7F, 0x7F, 0x7F)) {
+, colors(count, Color(0x7F, 0x7F, 0x7F))
+, colorDirty(true) {
 
 }
 
diff --git a/src/world/World.h b/src/world/World.h
index 8a00f60..9953e46 100644
--- a/src/world/World.h
+++ b/src/world/World.h
@@ -24,12 +24,19 @@ public:
 
 	bool InBounds(Vector<int> pos) const
 		{ return pos.x > 0 && pos.y > 0 && pos.x < size.x && pos.y < size.y; }
-	int Index(Vector<int> pos) const { return pos.x * size.y + pos.y; }
+	int Index(Vector<int> pos) const { return pos.y * size.x + pos.x; }
 
 	float MassAt(Vector<int> pos) const { return masses[Index(pos)]; }
 	void SetMass(Vector<int> pos, float m) { masses[Index(pos)] = m; }
+
 	Color ColorAt(Vector<int> pos) const { return colors[Index(pos)]; }
-	void SetColor(Vector<int> pos, Color c) { colors[Index(pos)] = c; }
+	const Color *GetColors() const { return colors.data(); }
+	void SetColor(Vector<int> pos, Color c) {
+		colors[Index(pos)] = c;
+		colorDirty = true;
+	}
+	bool ColorDirty() const { return colorDirty; }
+	void CleanColor() { colorDirty = false; }
 
 	const std::list<Entity> &Entities() const { return entities; }
 	Entity &AddEntity(const Entity &);
@@ -45,6 +52,7 @@ private:
 
 	std::vector<float> masses;
 	std::vector<Color> colors;
+	bool colorDirty;
 
 	std::list<Entity> entities;