From 03d706c0cb9809e72da092cc46cba2207b8b8848 Mon Sep 17 00:00:00 2001
From: unknown <115050813@qq.com>
Date: Sat, 13 Apr 2024 17:28:12 +0800
Subject: [PATCH] feat: clean line alias on tile border

---
 lib/src/main/resources/Shader/Tiled.frag      | 24 +++++++++++++++++--
 lib/src/main/resources/Shader/Tiled.vert      | 16 +++++--------
 .../jmecn/tiled/app/TmxLoaderExample.java     |  2 +-
 3 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/lib/src/main/resources/Shader/Tiled.frag b/lib/src/main/resources/Shader/Tiled.frag
index 3858f18..882b40e 100644
--- a/lib/src/main/resources/Shader/Tiled.frag
+++ b/lib/src/main/resources/Shader/Tiled.frag
@@ -13,13 +13,33 @@ uniform vec4 m_Color;
 uniform sampler2D m_ColorMap;
 #endif
 
-varying vec2 texCoord;
+#ifdef USE_TILESET_IMAGE
+uniform vec2 m_ImageSize;
+uniform vec4 m_TileSize;//(width, height, margin, space)
+varying vec2 v_TilePos;
+#endif
+
+varying vec2 v_TexCoord;
+
+vec2 getTileUVClamped(vec2 tilePos, vec2 tileSize, vec2 imageSize) {
+    vec2 pixel = v_TexCoord * tileSize + tilePos;
+    vec2 min = vec2(tilePos + 0.5);
+    vec2 max = vec2(tilePos + tileSize - 0.5);
+    vec2 uv = clamp(pixel, min, max) / imageSize;
+    uv.y = 1.0 - uv.y;
+    return uv;
+}
 
 void main(){
     vec4 color = vec4(1.0);
 
     #ifdef HAS_COLOR_MAP
-    vec2 uv = texCoord;
+    vec2 uv = v_TexCoord;
+
+    #ifdef USE_TILESET_IMAGE
+    uv = getTileUVClamped(v_TilePos, m_TileSize.xy, m_ImageSize.xy);
+    #endif
+
     color *= texture2D(m_ColorMap, uv);
     #endif
 
diff --git a/lib/src/main/resources/Shader/Tiled.vert b/lib/src/main/resources/Shader/Tiled.vert
index e99ccfc..3172971 100644
--- a/lib/src/main/resources/Shader/Tiled.vert
+++ b/lib/src/main/resources/Shader/Tiled.vert
@@ -3,25 +3,21 @@
 
 attribute vec3 inPosition;
 attribute vec2 inTexCoord;
-attribute vec4 inColor;
 
 #ifdef USE_TILESET_IMAGE
+// use texcoord2 as tile position
 attribute vec3 inTexCoord2;
-uniform vec2 m_ImageSize;
-uniform vec4 m_TileSize;
+// pass it to fragment shader
+varying vec2 v_TilePos;
 #endif
 
-varying vec2 texCoord;
+varying vec2 v_TexCoord;
 
 void main() {
-    texCoord = inTexCoord;
+    v_TexCoord = inTexCoord;
 
     #ifdef USE_TILESET_IMAGE
-    // calculate the UV coordinates for the tileset image
-    vec2 tilePos = inTexCoord2.xy;
-    vec2 uv = (texCoord * m_TileSize.xy + tilePos) / m_ImageSize.xy;
-    uv.y = 1.0 - uv.y;
-    texCoord = uv;
+    v_TilePos = inTexCoord2.xy;
     #endif
 
     vec3 position = inPosition;
diff --git a/lib/src/test/java/io/github/jmecn/tiled/app/TmxLoaderExample.java b/lib/src/test/java/io/github/jmecn/tiled/app/TmxLoaderExample.java
index 9de0db3..6a10c85 100644
--- a/lib/src/test/java/io/github/jmecn/tiled/app/TmxLoaderExample.java
+++ b/lib/src/test/java/io/github/jmecn/tiled/app/TmxLoaderExample.java
@@ -26,7 +26,7 @@ public void simpleInitApp() {
 
         TiledMapAppState tiledMap = stateManager.getState(TiledMapAppState.class);
         tiledMap.setMap(map);
-        tiledMap.setViewColumn(20);
+        //tiledMap.setViewColumn(20);
     }
 
     public static void main(String[] args) {