New example: font_filters

examples/text/font_filters/main.go

@@ -0,0 +1,125 @@
+/*******************************************************************************************
+*
+*   raylib [text] example - Font filters
+*
+*   NOTE: After font loading, font texture atlas filter could be configured for a softer
+*   display of the font when scaling it to different sizes, that way, it's not required
+*   to generate multiple fonts at multiple sizes (as long as the scaling is not very different)
+*
+*   Example originally created with raylib 1.3, last time updated with raylib 4.2
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2015-2024 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+package main
+
+import (
+	"fmt"
+	"path/filepath"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+const (
+	screenWidth  = 800
+	screenHeight = 450
+)
+
+func main() {
+	rl.InitWindow(screenWidth, screenHeight, "raylib [text] example - font filters")
+	msg := "Loaded Font"
+
+	// NOTE: Textures/Fonts MUST be loaded after Window initialization (OpenGL context is required)
+
+	// TTF Font loading with custom generation parameters
+	font := rl.LoadFontEx("KAISG.ttf", 96, nil, 0)
+
+	// Generate mipmap levels to use trilinear filtering
+	// NOTE: On 2D drawing it won't be noticeable, it looks like FILTER_BILINEAR
+	rl.GenTextureMipmaps(&font.Texture)
+
+	fontSize := float32(font.BaseSize)
+	fontPosition := rl.Vector2{X: 40.0, Y: screenHeight/2.0 - 80.0}
+	textSize := rl.Vector2{}
+
+	// Setup texture scaling filter
+	rl.SetTextureFilter(font.Texture, rl.FilterPoint)
+	currentFontFilter := 0 // TEXTURE_FILTER_POINT
+
+	rl.SetTargetFPS(60)           // Set our game to run at 60 frames-per-second
+	for !rl.WindowShouldClose() { // Detect window close button or ESC key
+		fontSize += rl.GetMouseWheelMove() * 4.0
+
+		// Choose font texture filter method
+		if rl.IsKeyPressed(rl.KeyOne) {
+			rl.SetTextureFilter(font.Texture, rl.FilterPoint)
+			currentFontFilter = 0
+		} else if rl.IsKeyPressed(rl.KeyTwo) {
+			rl.SetTextureFilter(font.Texture, rl.FilterBilinear)
+			currentFontFilter = 1
+		} else if rl.IsKeyPressed(rl.KeyThree) {
+			// NOTE: Trilinear filter won't be noticed on 2D drawing
+			rl.SetTextureFilter(font.Texture, rl.FilterTrilinear)
+			currentFontFilter = 2
+		}
+
+		textSize = rl.MeasureTextEx(font, msg, fontSize, 0)
+
+		if rl.IsKeyDown(rl.KeyLeft) {
+			fontPosition.X -= 10
+		} else if rl.IsKeyDown(rl.KeyRight) {
+			fontPosition.X += 10
+		}
+
+		// Load a dropped TTF file dynamically (at current fontSize)
+		if rl.IsFileDropped() {
+			droppedFiles := rl.LoadDroppedFiles()
+
+			// NOTE: We only support first ttf file dropped
+			if filepath.Ext(droppedFiles[0]) == ".ttf" {
+				rl.UnloadFont(font)
+				font = rl.LoadFontEx(droppedFiles[0], int32(fontSize), nil, 0)
+			}
+
+			rl.UnloadDroppedFiles() // Unload file paths from memory
+		}
+
+		// Draw
+		rl.BeginDrawing()
+		rl.ClearBackground(rl.RayWhite)
+
+		rl.DrawText("Use mouse wheel to change font size", 20, 20, 10, rl.Gray)
+		rl.DrawText("Use KEY_RIGHT and KEY_LEFT to move text", 20, 40, 10, rl.Gray)
+		rl.DrawText("Use 1, 2, 3 to change texture filter", 20, 60, 10, rl.Gray)
+		rl.DrawText("Drop a new TTF font for dynamic loading", 20, 80, 10, rl.DarkGray)
+		rl.DrawTextEx(font, msg, fontPosition, fontSize, 0, rl.Black)
+
+		// TODO: It seems texSize measurement is not accurate due to chars offsets...
+		//rl.DrawRectangleLines(fontPosition.X, fontPosition.Y, textSize.X, textSize.Y, rl.Red);
+
+		rl.DrawRectangle(0, screenHeight-80, screenWidth, 80, rl.LightGray)
+		text := fmt.Sprintf("Font size: %02.02f", fontSize)
+		rl.DrawText(text, 20, screenHeight-50, 10, rl.DarkGray)
+		text = fmt.Sprintf("Text size: [%02.02f, %02.02f]", textSize.X, textSize.Y)
+		rl.DrawText(text, 20, screenHeight-30, 10, rl.DarkGray)
+		rl.DrawText("CURRENT TEXTURE FILTER:", 250, 400, 20, rl.Gray)
+
+		switch currentFontFilter {
+		case 0:
+			rl.DrawText("POINT", 570, 400, 20, rl.Black)
+		case 1:
+			rl.DrawText("BILINEAR", 570, 400, 20, rl.Black)
+		case 2:
+			rl.DrawText("TRILINEAR", 570, 400, 20, rl.Black)
+		}
+
+		rl.EndDrawing()
+	}
+
+	// De-Initialization
+	rl.UnloadFont(font) // Font unloading
+	rl.CloseWindow()    // Close window and OpenGL context
+}