use anisotropic filtering for raster tiles #1064 (#4443)

mapbox · Mar 21, 2017 · e0a66fb · e0a66fb
1 parent c189bbf
commit e0a66fb
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diff --git a/src/render/painter.js b/src/render/painter.js
@@ -113,6 +113,15 @@ class Painter {
         rasterBoundsArray.emplaceBack(EXTENT, EXTENT, 32767, 32767);
         this.rasterBoundsBuffer = Buffer.fromStructArray(rasterBoundsArray, Buffer.BufferType.VERTEX);
         this.rasterBoundsVAO = new VertexArrayObject();
+
+        this.extTextureFilterAnisotropic = (
+            gl.getExtension('EXT_texture_filter_anisotropic') ||
+            gl.getExtension('MOZ_EXT_texture_filter_anisotropic') ||
+            gl.getExtension('WEBKIT_EXT_texture_filter_anisotropic')
+        );
+        if (this.extTextureFilterAnisotropic) {
+            this.extTextureFilterAnisotropicMax = gl.getParameter(this.extTextureFilterAnisotropic.MAX_TEXTURE_MAX_ANISOTROPY_EXT);
+        }
     }
 
     /*

diff --git a/src/source/raster_tile_source.js b/src/source/raster_tile_source.js
@@ -90,6 +90,11 @@ class RasterTileSource extends Evented {
                 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
                 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
                 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+
+                if (this.map.painter.extTextureFilterAnisotropic) {
+                    gl.texParameterf(gl.TEXTURE_2D, this.map.painter.extTextureFilterAnisotropic.TEXTURE_MAX_ANISOTROPY_EXT, this.map.painter.extTextureFilterAnisotropicMax);
+                }
+
                 gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, img);
                 tile.texture.size = img.width;
             }