Позиционирование текста

src/main/kotlin/ru/dbotthepony/kstarbound/Main.kt

@@ -15,9 +15,7 @@ import ru.dbotthepony.kstarbound.freetype.FreeType
 import ru.dbotthepony.kstarbound.freetype.LoadFlag
 import ru.dbotthepony.kstarbound.gl.*
 import ru.dbotthepony.kstarbound.math.*
-import ru.dbotthepony.kstarbound.render.Camera
-import ru.dbotthepony.kstarbound.render.ChunkRenderer
-import ru.dbotthepony.kstarbound.render.TileRenderer
+import ru.dbotthepony.kstarbound.render.*
 import ru.dbotthepony.kstarbound.world.CHUNK_SIZE
 import ru.dbotthepony.kstarbound.world.CHUNK_SIZE_FF
 import ru.dbotthepony.kstarbound.world.ChunkTile
@@ -212,7 +210,7 @@ private fun loop() {
 		state.matrixStack.clear(viewportMatrixGUI.toMutableMatrix())
 
 		state.matrixStack.translateWithScale(z = 10f, y = 0f)
-		state.font.render("FPS: %.2f".format(framesPerSecond))
+		state.font.render("FPS: %.2f".format(framesPerSecond), y = 0f, scale = 0.5f)
 
 		glfwSwapBuffers(window) // swap the color buffers
 

src/main/kotlin/ru/dbotthepony/kstarbound/render/Font.kt

@@ -23,7 +23,7 @@ private fun breakLines(text: String): List<String> {
 		if (nextLineBreak == previousLineBreak) {
 			list.add("")
 		} else {
-			list.add(text.substring(previousLineBreak, nextLineBreak - 1))
+			list.add(text.substring(previousLineBreak, nextLineBreak))
 		}
 
 		if (text.length - 1 <= nextLineBreak) {
@@ -43,6 +43,14 @@ private fun breakLines(text: String): List<String> {
 
 data class TextSize(val width: Float, val height: Float)
 
+enum class TextAlignX {
+	LEFT, CENTER, RIGHT
+}
+
+enum class TextAlignY {
+	TOP, CENTER, BOTTOM
+}
+
 class Font(
 	val state: GLStateTracker,
 	val font: String = "./unpacked_assets/hobo.ttf",
@@ -72,11 +80,28 @@ class Font(
 		x: Float = 0f,
 		y: Float = 0f,
 
+		alignX: TextAlignX = TextAlignX.LEFT,
+		alignY: TextAlignY = TextAlignY.TOP,
+
 		scale: Float = 1f,
 		stack: Matrix4fStack = state.matrixStack,
 	): TextSize {
+		if (text.isEmpty())
+			return TextSize(0f, 0f)
+		else if (text.size == 1 && text[0] == "")
+			return TextSize(0f, lineHeight * scale)
+
+		val totalSize = size(text)
+		val totalX = totalSize.width * scale
+		val totalY = totalSize.height * scale
+
 		stack.push()
-		stack.translateWithScale(x = x, y = lineHeight + y)
+
+		when (alignY) {
+			TextAlignY.TOP -> stack.translateWithScale(x = x, y = lineHeight * scale + y)
+			TextAlignY.CENTER -> stack.translateWithScale(x = x, y = lineHeight * scale - totalY / 2f + y)
+			TextAlignY.BOTTOM -> stack.translateWithScale(x = x, y = lineHeight * scale - totalY + y)
+		}
 
 		if (scale != 1f)
 			stack.scale(x = scale, y = scale)
@@ -87,9 +112,29 @@ class Font(
 		val space = getGlyph(' ')
 
 		var advancedX = 0f
-		var advancedY = 0f
 
 		for (line in text) {
+			if (line == "") {
+				stack.translateWithScale(y = lineHeight)
+				continue
+			}
+
+			var movedX = 0f
+
+			when (alignX) {
+				TextAlignX.LEFT -> {}
+
+				TextAlignX.CENTER -> {
+					movedX = totalX / 2f - lineWidth(line, space) / 2f
+					stack.translateWithScale(x = movedX)
+				}
+
+				TextAlignX.RIGHT -> {
+					movedX = totalX - lineWidth(line, space)
+					stack.translateWithScale(x = movedX)
+				}
+			}
+
 			var lineGlyphs = 0
 			var lineWidth = 0f
 
@@ -114,14 +159,13 @@ class Font(
 			}
 
 			advancedX = advancedX.coerceAtLeast(lineWidth)
-			stack.translateWithScale(x = -lineWidth, y = lineHeight)
-			advancedY += lineHeight
+			stack.translateWithScale(x = -lineWidth - movedX, y = lineHeight)
 		}
 
 		state.VAO = null
 		stack.pop()
 
-		return TextSize(advancedX * scale, advancedY * scale)
+		return totalSize
 	}
 
 	fun render(
@@ -130,10 +174,38 @@ class Font(
 		x: Float = 0f,
 		y: Float = 0f,
 
+		alignX: TextAlignX = TextAlignX.LEFT,
+		alignY: TextAlignY = TextAlignY.TOP,
+
 		scale: Float = 1f,
 		stack: Matrix4fStack = state.matrixStack,
 	): TextSize {
-		return render(breakLines(text), x, y, scale, stack)
+		return render(breakLines(text), x, y, alignX, alignY, scale, stack)
+	}
+
+	private fun lineWidth(line: String, space: Glyph): Float {
+		var lineWidth = 0f
+		var lineGlyphs = 0
+
+		for (chr in line) {
+			if (chr == '\t') {
+				if (lineGlyphs % 4 == 0) {
+					lineWidth += space.advanceX * 4
+					state.matrixStack.translateWithScale(x = space.advanceX * 4)
+				} else {
+					lineWidth += space.advanceX * (lineGlyphs % 4)
+					state.matrixStack.translateWithScale(x = space.advanceX * (lineGlyphs % 4))
+				}
+
+				lineGlyphs += lineGlyphs % 4
+				continue
+			}
+
+			lineWidth += getGlyph(chr).advanceX
+			lineGlyphs++
+		}
+
+		return lineWidth
 	}
 
 	fun size(lines: List<String>): TextSize {
@@ -143,28 +215,7 @@ class Font(
 		val space = getGlyph(' ')
 
 		for (line in lines) {
-			var lineWidth = 0f
-			var lineGlyphs = 0
-
-			for (chr in line) {
-				if (chr == '\t') {
-					if (lineGlyphs % 4 == 0) {
-						advancedX += space.advanceX * 4
-						state.matrixStack.translateWithScale(x = space.advanceX * 4)
-					} else {
-						advancedX += space.advanceX * (lineGlyphs % 4)
-						state.matrixStack.translateWithScale(x = space.advanceX * (lineGlyphs % 4))
-					}
-
-					lineGlyphs += lineGlyphs % 4
-					continue
-				}
-
-				lineWidth += getGlyph(chr).advanceX
-				lineGlyphs++
-			}
-
-			advancedX = advancedX.coerceAtLeast(lineWidth)
+			advancedX = advancedX.coerceAtLeast(lineWidth(line, space))
 			advancedY += lineHeight
 		}