mapbox · ansis · Sep 10, 2018 · Aug 23, 2018
diff --git a/src/data/bucket/fill_extrusion_bucket.js b/src/data/bucket/fill_extrusion_bucket.js
@@ -197,7 +197,12 @@ class FillExtrusionBucket implements Bucket {
 
                             const bottomRight = segment.vertexLength;
 
-                            this.indexArray.emplaceBack(bottomRight, bottomRight + 1, bottomRight + 2);
+                            // ┌──────┐
+                            // │ 0  1 │ Counter-clockwise winding order.
+                            // │      │ Triangle 1: 0 => 2 => 1
+                            // │ 2  3 │ Triangle 2: 1 => 2 => 3
+                            // └──────┘
+                            this.indexArray.emplaceBack(bottomRight, bottomRight + 2, bottomRight + 1);
                             this.indexArray.emplaceBack(bottomRight + 1, bottomRight + 2, bottomRight + 3);
 
                             segment.vertexLength += 4;
@@ -238,10 +243,11 @@ class FillExtrusionBucket implements Bucket {
             assert(indices.length % 3 === 0);
 
             for (let j = 0; j < indices.length; j += 3) {
+                // Counter-clockwise winding order.
                 this.indexArray.emplaceBack(
                     triangleIndex + indices[j],
-                    triangleIndex + indices[j + 1],
-                    triangleIndex + indices[j + 2]);
+                    triangleIndex + indices[j + 2],
+                    triangleIndex + indices[j + 1]);
             }
 
             segment.primitiveLength += indices.length / 3;

diff --git a/src/gl/context.js b/src/gl/context.js
@@ -6,8 +6,9 @@ import Framebuffer from './framebuffer';
 import DepthMode from './depth_mode';
 import StencilMode from './stencil_mode';
 import ColorMode from './color_mode';
+import CullFaceMode from './cull_face_mode';
 import { deepEqual } from '../util/util';
-import { ClearColor, ClearDepth, ClearStencil, ColorMask, DepthMask, StencilMask, StencilFunc, StencilOp, StencilTest, DepthRange, DepthTest, DepthFunc, CullFace, Blend, BlendFunc, BlendColor, BlendEquation, Program, ActiveTextureUnit, Viewport, BindFramebuffer, BindRenderbuffer, BindTexture, BindVertexBuffer, BindElementBuffer, BindVertexArrayOES, PixelStoreUnpack, PixelStoreUnpackPremultiplyAlpha, PixelStoreUnpackFlipY } from './value';
+import { ClearColor, ClearDepth, ClearStencil, ColorMask, DepthMask, StencilMask, StencilFunc, StencilOp, StencilTest, DepthRange, DepthTest, DepthFunc, Blend, BlendFunc, BlendColor, BlendEquation, CullFace, CullFaceSide, FrontFace, Program, ActiveTextureUnit, Viewport, BindFramebuffer, BindRenderbuffer, BindTexture, BindVertexBuffer, BindElementBuffer, BindVertexArrayOES, PixelStoreUnpack, PixelStoreUnpackPremultiplyAlpha, PixelStoreUnpackFlipY } from './value';
 
 
 import type {TriangleIndexArray, LineIndexArray, LineStripIndexArray} from '../data/index_array_type';
@@ -41,11 +42,13 @@ class Context {
     depthRange: DepthRange;
     depthTest: DepthTest;
     depthFunc: DepthFunc;
-    cullFace: CullFace;
     blend: Blend;
     blendFunc: BlendFunc;
     blendColor: BlendColor;
     blendEquation: BlendEquation;
+    cullFace: CullFace;
+    cullFaceSide: CullFaceSide;
+    frontFace: FrontFace;
     program: Program;
     activeTexture: ActiveTextureUnit;
     viewport: Viewport;
@@ -79,11 +82,13 @@ class Context {
         this.depthRange = new DepthRange(this);
         this.depthTest = new DepthTest(this);
         this.depthFunc = new DepthFunc(this);
-        this.cullFace = new CullFace(this);
         this.blend = new Blend(this);
         this.blendFunc = new BlendFunc(this);
         this.blendColor = new BlendColor(this);
         this.blendEquation = new BlendEquation(this);
+        this.cullFace = new CullFace(this);
+        this.cullFaceSide = new CullFaceSide(this);
+        this.frontFace = new FrontFace(this);
         this.program = new Program(this);
         this.activeTexture = new ActiveTextureUnit(this);
         this.viewport = new Viewport(this);
@@ -126,11 +131,13 @@ class Context {
         this.depthRange.dirty = true;
         this.depthTest.dirty = true;
         this.depthFunc.dirty = true;
-        this.cullFace.dirty = true;
         this.blend.dirty = true;
         this.blendFunc.dirty = true;
         this.blendColor.dirty = true;
         this.blendEquation.dirty = true;
+        this.cullFace.dirty = true;
+        this.cullFaceSide.dirty = true;
+        this.frontFace.dirty = true;
         this.program.dirty = true;
         this.activeTexture.dirty = true;
         this.viewport.dirty = true;
@@ -196,6 +203,16 @@ class Context {
         gl.clear(mask);
     }
 
+    setCullFace(cullFaceMode: $ReadOnly<CullFaceMode>) {
+        if (cullFaceMode.enable === false) {
+            this.cullFace.set(false);
+        } else {
+            this.cullFace.set(true);
+            this.cullFaceSide.set(cullFaceMode.mode);
+            this.frontFace.set(cullFaceMode.frontFace);
+        }
+    }
+
     setDepthMode(depthMode: $ReadOnly<DepthMode>) {
         if (depthMode.func === this.gl.ALWAYS && !depthMode.mask) {
             this.depthTest.set(false);

diff --git a/src/gl/cull_face_mode.js b/src/gl/cull_face_mode.js
@@ -0,0 +1,26 @@
+// @flow
+
+import type {CullFaceModeType, FrontFaceType} from './types';
+
+const BACK = 0x0405;
+const CCW = 0x0901;
+
+class CullFaceMode {
+    enable: boolean;
+    mode: CullFaceModeType;
+    frontFace: FrontFaceType;
+
+    constructor(enable: boolean, mode: CullFaceModeType, frontFace: FrontFaceType) {
+        this.enable = enable;
+        this.mode = mode;
+        this.frontFace = frontFace;
+    }
+
+    static disabled: $ReadOnly<CullFaceMode>;
+    static backCCW: $ReadOnly<CullFaceMode>;
+}
+
+CullFaceMode.disabled = new CullFaceMode(false, BACK, CCW);
+CullFaceMode.backCCW = new CullFaceMode(true, BACK, CCW);
+
+export default CullFaceMode;
diff --git a/src/gl/types.js b/src/gl/types.js
@@ -73,3 +73,12 @@ export type StencilTest =
     | { func: $PropertyType<WebGLRenderingContext, 'NOTEQUAL'>, mask: number }
     | { func: $PropertyType<WebGLRenderingContext, 'GEQUAL'>, mask: number }
     | { func: $PropertyType<WebGLRenderingContext, 'ALWAYS'>, mask: 0 };
+
+export type CullFaceModeType =
+    | $PropertyType<WebGLRenderingContext, 'FRONT'>
+    | $PropertyType<WebGLRenderingContext, 'BACK'>
+    | $PropertyType<WebGLRenderingContext, 'FRONT_AND_BACK'>
+
+export type FrontFaceType =
+    | $PropertyType<WebGLRenderingContext, 'CW'>
+    | $PropertyType<WebGLRenderingContext, 'CCW'>
diff --git a/src/gl/value.js b/src/gl/value.js
@@ -14,6 +14,8 @@ import type {
     DepthFuncType,
     TextureUnitType,
     ViewportType,
+    CullFaceModeType,
+    FrontFaceType,
 } from './types';
 
 export interface Value<T> {
@@ -358,37 +360,6 @@ export class DepthFunc implements Value<DepthFuncType> {
     }
 }
 
-export class CullFace implements Value<boolean> {
-    context: Context;
-    current: boolean;
-    default: boolean;
-    dirty: boolean;
-
-    constructor(context: Context) {
-        this.context = context;
-        this.default = false;
-        this.current = this.default;
-        this.dirty = false;
-    }
-
-    get(): boolean { return this.current; }
-
-    setDefault(): void { this.set(this.default); }
-
-    set(v: boolean): void {
-        if (this.current !== v || this.dirty === true) {
-            const gl = this.context.gl;
-            if (v) {
-                gl.enable(gl.CULL_FACE);
-            } else {
-                gl.disable(gl.CULL_FACE);
-            }
-            this.current = v;
-            this.dirty = false;
-        }
-    }
-}
-
 export class Blend implements Value<boolean> {
     context: Context;
     current: boolean;
@@ -501,6 +472,93 @@ export class BlendEquation implements Value<BlendEquationType> {
     }
 }
 
+export class CullFace implements Value<boolean> {
+    context: Context;
+    current: boolean;
+    default: boolean;
+    dirty: boolean;
+
+    constructor(context: Context) {
+        this.context = context;
+        this.default = false;
+        this.current = this.default;
+        this.dirty = false;
+    }
+
+    get(): boolean { return this.current; }
+
+    setDefault(): void { this.set(this.default); }
+
+    set(v: boolean): void {
+        if (this.current !== v || this.dirty === true) {
+            const gl = this.context.gl;
+            if (v) {
+                gl.enable(gl.CULL_FACE);
+            } else {
+                gl.disable(gl.CULL_FACE);
+            }
+            this.current = v;
+            this.dirty = false;
+        }
+    }
+}
+
+export class CullFaceSide implements Value<CullFaceModeType> {
+    context: Context;
+    current: CullFaceModeType;
+    default: CullFaceModeType;
+    dirty: boolean;
+
+    constructor(context: Context) {
+        this.context = context;
+        const gl = this.context.gl;
+        this.default = gl.BACK;
+        this.current = this.default;
+        this.dirty = false;
+    }
+
+    get(): CullFaceModeType { return this.current; }
+
+    setDefault(): void { this.set(this.default); }
+
+    set(v: CullFaceModeType): void {
+        if (this.current !== v || this.dirty === true) {
+            const gl = this.context.gl;
+            gl.cullFace(v);
+            this.current = v;
+            this.dirty = false;
+        }
+    }
+}
+
+export class FrontFace implements Value<FrontFaceType> {
+    context: Context;
+    current: FrontFaceType;
+    default: FrontFaceType;
+    dirty: boolean;
+
+    constructor(context: Context) {
+        this.context = context;
+        const gl = this.context.gl;
+        this.default = gl.CCW;
+        this.current = this.default;
+        this.dirty = false;
+    }
+
+    get(): FrontFaceType { return this.current; }
+
+    setDefault(): void { this.set(this.default); }
+
+    set(v: FrontFaceType): void {
+        if (this.current !== v || this.dirty === true) {
+            const gl = this.context.gl;
+            gl.frontFace(v);
+            this.current = v;
+            this.dirty = false;
+        }
+    }
+}
+
 export class Program implements Value<?WebGLProgram> {
     context: Context;
     current: ?WebGLProgram;

diff --git a/src/render/draw_background.js b/src/render/draw_background.js
@@ -2,6 +2,7 @@
 
 import StencilMode from '../gl/stencil_mode';
 import DepthMode from '../gl/depth_mode';
+import CullFaceMode from '../gl/cull_face_mode';
 import {
     backgroundUniformValues,
     backgroundPatternUniformValues
@@ -50,7 +51,7 @@ function drawBackground(painter: Painter, sourceCache: SourceCache, layer: Backg
             backgroundPatternUniformValues(matrix, opacity, painter, image, {tileID, tileSize}, crossfade) :
             backgroundUniformValues(matrix, opacity, color);
 
-        program.draw(context, gl.TRIANGLES, depthMode, stencilMode, colorMode,
+        program.draw(context, gl.TRIANGLES, depthMode, stencilMode, colorMode, CullFaceMode.disabled,
             uniformValues, layer.id, painter.tileExtentBuffer,
             painter.quadTriangleIndexBuffer, painter.tileExtentSegments);
     }

diff --git a/src/render/draw_circle.js b/src/render/draw_circle.js
@@ -2,6 +2,7 @@
 
 import StencilMode from '../gl/stencil_mode';
 import DepthMode from '../gl/depth_mode';
+import CullFaceMode from '../gl/cull_face_mode';
 import { circleUniformValues } from './program/circle_program';
 
 import type Painter from './painter';
@@ -42,7 +43,7 @@ function drawCircles(painter: Painter, sourceCache: SourceCache, layer: CircleSt
         const programConfiguration = bucket.programConfigurations.get(layer.id);
         const program = painter.useProgram('circle', programConfiguration);
 
-        program.draw(context, gl.TRIANGLES, depthMode, stencilMode, colorMode,
+        program.draw(context, gl.TRIANGLES, depthMode, stencilMode, colorMode, CullFaceMode.disabled,
             circleUniformValues(painter, coord, tile, layer), layer.id,
             bucket.layoutVertexBuffer, bucket.indexBuffer, bucket.segments,
             layer.paint, painter.transform.zoom, programConfiguration);

diff --git a/src/render/draw_collision_debug.js b/src/render/draw_collision_debug.js
@@ -7,6 +7,7 @@ import type {OverscaledTileID} from '../source/tile_id';
 import type SymbolBucket from '../data/bucket/symbol_bucket';
 import DepthMode from '../gl/depth_mode';
 import StencilMode from '../gl/stencil_mode';
+import CullFaceMode from '../gl/cull_face_mode';
 import { collisionUniformValues } from './program/collision_program';
 
 export default drawCollisionDebug;
@@ -27,6 +28,7 @@ function drawCollisionDebugGeometry(painter: Painter, sourceCache: SourceCache,
         program.draw(context, drawCircles ? gl.TRIANGLES : gl.LINES,
             DepthMode.disabled, StencilMode.disabled,
             painter.colorModeForRenderPass(),
+            CullFaceMode.disabled,
             collisionUniformValues(
                 coord.posMatrix,
                 painter.transform,

diff --git a/src/render/draw_debug.js b/src/render/draw_debug.js
@@ -8,6 +8,7 @@ import posAttributes from '../data/pos_attributes';
 import SegmentVector from '../data/segment';
 import DepthMode from '../gl/depth_mode';
 import StencilMode from '../gl/stencil_mode';
+import CullFaceMode from '../gl/cull_face_mode';
 import { debugUniformValues } from './program/debug_program';
 import Color from '../style-spec/util/color';
 
@@ -35,7 +36,7 @@ function drawDebugTile(painter, sourceCache, coord) {
     const colorMode = painter.colorModeForRenderPass();
     const id = '$debug';
 
-    program.draw(context, gl.LINE_STRIP, depthMode, stencilMode, colorMode,
+    program.draw(context, gl.LINE_STRIP, depthMode, stencilMode, colorMode, CullFaceMode.disabled,
         debugUniformValues(posMatrix, Color.red), id,
         painter.debugBuffer, painter.tileBorderIndexBuffer, painter.debugSegments);
 
@@ -58,7 +59,7 @@ function drawDebugTile(painter, sourceCache, coord) {
     for (let i = 0; i < translations.length; i++) {
         const translation = translations[i];
 
-        program.draw(context, gl.LINES, depthMode, stencilMode, colorMode,
+        program.draw(context, gl.LINES, depthMode, stencilMode, colorMode, CullFaceMode.disabled,
             debugUniformValues(
                 mat4.translate([], posMatrix, [
                     onePixel * translation[0],
@@ -67,7 +68,7 @@ function drawDebugTile(painter, sourceCache, coord) {
             id, debugTextBuffer, debugTextIndexBuffer, debugTextSegment);
     }
 
-    program.draw(context, gl.LINES, depthMode, stencilMode, colorMode,
+    program.draw(context, gl.LINES, depthMode, stencilMode, colorMode, CullFaceMode.disabled,
         debugUniformValues(posMatrix, Color.black), id,
         debugTextBuffer, debugTextIndexBuffer, debugTextSegment);
 }

diff --git a/src/render/draw_fill.js b/src/render/draw_fill.js
@@ -2,6 +2,7 @@
 
 import Color from '../style-spec/util/color';
 import DepthMode from '../gl/depth_mode';
+import CullFaceMode from '../gl/cull_face_mode';
 import {
     fillUniformValues,
     fillPatternUniformValues,
@@ -116,7 +117,7 @@ function drawFillTiles(painter, sourceCache, layer, coords, depthMode, colorMode
         }
 
         program.draw(painter.context, drawMode, depthMode,
-            painter.stencilModeForClipping(coord), colorMode, uniformValues,
+            painter.stencilModeForClipping(coord), colorMode, CullFaceMode.disabled, uniformValues,
             layer.id, bucket.layoutVertexBuffer, indexBuffer, segments,
             layer.paint, painter.transform.zoom, programConfiguration);
     }