added integer scaling window

com/danitheskunk/skunkworks/Test.java

@@ -8,7 +8,7 @@ public class Test extends BaseGame {
 	private Terminal term;
 
 	public Test() {
-		super(new Vec2i(1280, 720), "Skunkworks");
+		super(new Vec2i(1280/2, 720/2), "Skunkworks");
 	}
 
 	public static void main(String[] args) {
@@ -19,7 +19,7 @@ public class Test extends BaseGame {
 	protected void init() {
 		var fontThin = window.loadFontTileset("fonts\\thin-6x12.png");
 		var fontThin2 = window.loadFontTileset("fonts\\thin-12x12.png");
-		term = new Terminal(new Vec2i(80, 45), fontThin2, fontThin);
+		term = new Terminal(new Vec2i(80/2, 45/2), fontThin2, fontThin);
 
 		var c1 = Color.GREEN;
 		var c2 = new Color(0, 128, 0);

com/danitheskunk/skunkworks/backends/gl/TextureAtlas.java

@@ -17,14 +17,15 @@ class TextureAtlas {
 	private Texture atlasTexture; //for debugging
 	private Image img;
 	private boolean shouldUpdate;
+	final private int textureID;
 
 	TextureAtlas() {
 		img = new Image(new Vec2i(32, 32));
-		int textureID = glGenTextures();
+		textureID = glGenTextures();
 		textures = new ArrayList<>();
 		shouldUpdate = true;
 
-		glBindTexture(GL_TEXTURE_2D, textureID);
+		bind();
 		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
@@ -32,6 +33,10 @@ class TextureAtlas {
 
 	}
 
+	public void bind() {
+		glBindTexture(GL_TEXTURE_2D, textureID);
+	}
+
 	ITexture addTexture(Image img) {
 		//todo: do the actual texture stuff
 		//this.img = img;

com/danitheskunk/skunkworks/backends/gl/Window.java

@@ -8,6 +8,7 @@ import com.danitheskunk.skunkworks.gfx.IRenderContext;
 import com.danitheskunk.skunkworks.gfx.ITexture;
 import com.danitheskunk.skunkworks.gfx.Image;
 import org.lwjgl.glfw.GLFWErrorCallback;
+import org.lwjgl.glfw.GLFWWindowCloseCallbackI;
 import org.lwjgl.opengl.GL;
 import org.lwjgl.opengl.GL11;
 
@@ -44,13 +45,42 @@ public class Window extends BaseWindow {
 					color = texelFetch(tex, ivec2(mod(texCoord, texSize)) + texOffset, 0) * vec4(tint, 1.0f);
 				}
 		""";
+
+	private static String vertexSourceScaler = """
+		#version 450
+		layout(location = 0) in vec2 pos;
+		layout(location = 1) in vec2 texCoord;
+		layout(location = 2) uniform vec2 windowSize;
+		layout(location = 1) out vec2 out_texCoord;
+		void main() {
+			gl_Position = vec4(pos / windowSize * vec2(2.0f, 2.0f) + vec2(-1.0f, -1.0f), 0.0f, 1.0f);
+			out_texCoord = texCoord;
+		}
+		""";
+	private static String fragmentSourceScaler = """
+				#version 450
+				layout(location = 1) in vec2 texCoord;
+				layout(binding = 0) uniform sampler2D tex;
+				out vec4 color;
+				void main() {
+					//color = vec4(vec2(texCoord).x/1000.f, 0.2f, 0.7f, 1.0f);
+					color = texture(tex, texCoord);
+					//color = texelFetch(tex, ivec2(texCoord), 0);
+					//color = vec4(1.0, 1.0, 1.0, 1.0);
+					//color = vec4(texCoord.xy, 0.0, 1.0);
+				}
+		""";
 	private final Program program;
+	private final Program programScaler;
 	private final RenderContext renderContext;
 	private final Vec2i size;
+	private Vec2i windowSize;
 	private final TextureAtlas textureAtlas;
 	private final long window;
 	private boolean debug;
 	private boolean shouldClose;
+	private final int framebuffer;
+	private final int framebufferTex;
 
 	public Window(Vec2i size, String title, Engine engine) {
 		super(engine);
@@ -61,6 +91,7 @@ public class Window extends BaseWindow {
 		glfwDefaultWindowHints();
 		this.debug = false;
 		this.size = size;
+		this.windowSize = size;
 
 		window = glfwCreateWindow(size.getX(), size.getY(), title, NULL, NULL);
 		if(window == NULL) throw new RuntimeException(
@@ -79,9 +110,36 @@ public class Window extends BaseWindow {
 		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 		glEnable(GL_BLEND);
 
+		glfwSetWindowSizeCallback(window, this::windowSizeCallback);
+
+
+		framebuffer = glGenFramebuffers();
+		glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+		framebufferTex = glGenTextures();
+		glBindTexture(GL_TEXTURE_2D, framebufferTex);
+		glTexImage2D(GL_TEXTURE_2D,
+			0,
+			GL_RGB,
+			size.getX(),
+			size.getY(),
+			0,
+			GL_RGB,
+			GL_UNSIGNED_BYTE,
+			0
+		);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		glFramebufferTexture(GL_FRAMEBUFFER,
+			GL_COLOR_ATTACHMENT0,
+			framebufferTex,
+			0
+		);
+		glDrawBuffers(GL_COLOR_ATTACHMENT0);
+
 		textureAtlas = new TextureAtlas();
 		program = new Program(vertexSource, fragmentSource);
-		program.use();
+		programScaler = new Program(vertexSourceScaler, fragmentSourceScaler);
+
 		renderContext = new RenderContext(size,
 			textureAtlas,
 			program.getAttribLocation("texCoord"),
@@ -89,8 +147,7 @@ public class Window extends BaseWindow {
 			program.getUniformLocation("texSize"),
 			program.getUniformLocation("tint")
 		);
-		glProgramUniform2f(
+		glProgramUniform2f(program.program,
-			program.program,
 			program.getUniformLocation("windowSize"),
 			size.getX(),
 			size.getY()
@@ -103,6 +160,14 @@ public class Window extends BaseWindow {
 		System.out.println(GL11.glGetInteger(GL_MAX_TEXTURE_SIZE));
 	}
 
+	private void windowSizeCallback(long window, int width, int height) {
+		System.out.printf("new window size %d x %d\n", width, height);
+		windowSize = new Vec2i(width, height);
+		glViewport(0, 0, width, height);
+		//glLoadIdentity();
+		//glOrtho(0.0f, width, height, 0.0f, 0.0f, 1.0f);
+	}
+
 	@Override
 	public ITexture loadTexture(Image image) {
 		return textureAtlas.addTexture(image);
@@ -121,8 +186,7 @@ public class Window extends BaseWindow {
 
 		for(int y = 0; y < tileCount.getY(); ++y) {
 			for(int x = 0; x < tileCount.getX(); ++x) {
-				var rect = new Recti(
+				var rect = new Recti(Vec2i.mul(new Vec2i(x, y), tileSize),
-					Vec2i.mul(new Vec2i(x, y), tileSize),
 					tileSize
 				);
 				var img = image.getSubImage(rect);
@@ -142,18 +206,66 @@ public class Window extends BaseWindow {
 	@Override
 	public void renderFinish(IRenderContext context) {
 		if(debug) {
-			context.drawTextureRectangle(
+			context.drawTextureRectangle(new Recti(Vec2i.ZERO, size),
-				new Recti(Vec2i.ZERO, size),
 				textureAtlas.getAtlasTexture(),
 				true
 			);
 		}
 		//glEnd();
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+		glViewport(0, 0, windowSize.getX(), windowSize.getY());
+		programScaler.use();
+		glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT);
+
+		glBindTexture(GL_TEXTURE_2D, framebufferTex);
+		glProgramUniform2f(programScaler.program,
+			programScaler.getUniformLocation("windowSize"),
+			windowSize.getX(),
+			windowSize.getY()
+		);
+
+		int scalex = windowSize.getX() / size.getX();
+		int scaley = windowSize.getY() / size.getY();
+		int scale = Math.max(1, Math.min(scalex, scaley));
+
+		int xoff = (windowSize.getX() - size.getX() * scale) / 2;
+		int yoff = (windowSize.getY() - size.getY() * scale) / 2;
+
+		int tlx1 = xoff;
+		int tly1 = yoff;
+		int tlx2 = xoff + size.getX() * scale;
+		int tly2 = yoff + size.getY() * scale;
+
+
+		var texCoordIndex = programScaler.getAttribLocation("texCoord");
+		glBegin(GL_TRIANGLES);
+		//counterclockwise triangles
+		glVertexAttrib2f(texCoordIndex, 0, 1);
+		glVertex2i(tlx1, tly2);
+		glVertexAttrib2f(texCoordIndex, 1, 0);
+		glVertex2i(tlx2, tly1);
+		glVertexAttrib2f(texCoordIndex, 0, 0);
+		glVertex2i(tlx1, tly1);
+
+		glVertexAttrib2f(texCoordIndex, 1, 0);
+		glVertex2i(tlx2, tly1);
+		glVertexAttrib2f(texCoordIndex, 0, 1);
+		glVertex2i(tlx1, tly2);
+		glVertexAttrib2f(texCoordIndex, 1, 1);
+		glVertex2i(tlx2, tly2);
+
+		glEnd();
+
 		glfwSwapBuffers(window);
 	}
 
 	@Override
 	public IRenderContext renderStart() {
+		program.use();
+		textureAtlas.bind();
+		glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+		glViewport(0, 0, size.getX(), size.getY());
 		textureAtlas.update();
 		glClearColor(0.f, 0.f, 0.f, 1.0f);
 		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);