Test: Font renderer

Author: emyfops

common/src/main/kotlin/com/lambda/graphics/renderer/gui/font/FontRenderer.kt

@@ -140,8 +140,13 @@ class FontRenderer(
 
     override fun render() {
         shader.use()
+
         font.glyphs.bind()
-        //emojis.glyphs.bind() // You have to modify the uniform in the shader to use the correct texture
+        shader["u_FontTexture"] = 0
+
+        emojis.glyphs.bind()
+        shader["u_EmojiTexture"] = 1
+
         super.render()
     }
 

common/src/main/kotlin/com/lambda/graphics/renderer/gui/font/glyph/CharInfo.kt

@@ -6,4 +6,4 @@ class CharInfo(
     val size: Vec2d,
     val uv1: Vec2d,
     val uv2: Vec2d
-)
+)

common/src/main/kotlin/com/lambda/graphics/renderer/gui/font/glyph/EmojiGlyphs.kt

@@ -55,7 +55,7 @@ class EmojiGlyphs(zipUrl: String) {
 
                     val uv1 = Vec2d(x.toDouble(), y.toDouble()) * texelSize
                     val uv2 = Vec2d(x, y).plus(dimensions) * texelSize
-                    emojiMap[name] = CharInfo(dimensions, uv1, uv2)
+                    emojiMap[name] = CharInfo(dimensions, uv1 * -1.0, uv2 * -1.0)
 
                     x += emoji.width
                 }
@@ -69,11 +69,15 @@ class EmojiGlyphs(zipUrl: String) {
 
     fun bind() {
         with(fontTexture) {
-            bind()
+            bind(GL_TEXTURE_SLOT)
             setLOD(FontSettings.lodBias.toFloat())
         }
     }
 
     fun getEmoji(emoji: String): CharInfo? =
         emojiMap[emoji]
+
+    companion object {
+        private const val GL_TEXTURE_SLOT = 1
+    }
 }

common/src/main/kotlin/com/lambda/graphics/renderer/gui/font/glyph/FontGlyphs.kt

@@ -63,7 +63,7 @@ class FontGlyphs(font: Font) {
 
     fun bind() {
         with(fontTexture) {
-            bind()
+            bind(GL_TEXTURE_SLOT)
             setLOD(FontSettings.lodBias.toFloat())
         }
     }
@@ -72,6 +72,9 @@ class FontGlyphs(font: Font) {
         charMap[char.code]
 
     companion object {
+        // The allocated texture slot
+        private const val GL_TEXTURE_SLOT = 0
+
         // The space between glyphs is necessary to prevent artifacts from appearing when the font texture is blurred
         private const val STEP = 2
 

common/src/main/kotlin/com/lambda/graphics/texture/Texture.kt

@@ -14,7 +14,7 @@ abstract class Texture {
 
     protected abstract fun init()
 
-    open fun bind() = bindTexture(id)
+    open fun bind(slot: Int = 0) = bindTexture(id)
 
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
@@ -26,4 +26,4 @@ abstract class Texture {
     }
 
     override fun hashCode() = id
-}
+}

common/src/main/resources/assets/lambda/shaders/fragment/renderer/font.frag

@@ -1,13 +1,21 @@
 #version 330 core
 
-uniform sampler2D u_Texture;
+uniform sampler2D u_FontTexture;
+uniform sampler2D u_EmojiTexture;
 
 in vec2 v_TexCoord;
 in vec4 v_Color;
 
 out vec4 color;
 
 void main() {
-    float alpha = texture(u_Texture, v_TexCoord).a;
-    color = vec4(v_Color.rgb, v_Color.a * alpha);
-}
+    vec4 tex;
+
+    if (v_TexCoord.x > 0.0) {
+        tex = texture(u_FontTexture, v_TexCoord);
+    } else {
+        tex = texture(u_EmojiTexture, v_TexCoord);
+    }
+
+    color = tex * v_Color;
+}