experiment: remove stencil-buffer based clippingupstream/drop-stencil-clipping

[skip ci]

9 files changed, 3 insertions, 91 deletions

diff --git a/src/mbgl/map/source.cpp b/src/mbgl/map/source.cpp
index 518468af6e..3abdf810f3 100644
--- a/src/mbgl/map/source.cpp
+++ b/src/mbgl/map/source.cpp
@@ -183,14 +183,6 @@ void Source::updateMatrices(const mat4 &projMatrix, const TransformState &transf
     }
 }
 
-void Source::drawClippingMasks(Painter &painter) {
-    for (const auto& pair : tiles) {
-        Tile &tile = *pair.second;
-        MBGL_DEBUG_GROUP(std::string { "mask: " } + std::string(tile.id));
-        painter.drawClippingMask(tile.matrix, tile.clip);
-    }
-}
-
 void Source::finishRender(Painter &painter) {
     for (const auto& pair : tiles) {
         Tile &tile = *pair.second;
diff --git a/src/mbgl/renderer/painter.cpp b/src/mbgl/renderer/painter.cpp
index 8011dfd05f..a39a68415a 100644
--- a/src/mbgl/renderer/painter.cpp
+++ b/src/mbgl/renderer/painter.cpp
@@ -80,10 +80,6 @@ void Painter::setup() {
     // Set clear values
     config.clearColor = { 0.0f, 0.0f, 0.0f, 0.0f };
     config.clearDepth = 1.0f;
-    config.clearStencil = 0x0;
-
-    // Stencil test
-    MBGL_CHECK_ERROR(glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE));
 
     // Depth test
     glDepthFunc(GL_LEQUAL);
@@ -148,24 +144,16 @@ void Painter::changeMatrix() {
 
 void Painter::clear() {
     MBGL_DEBUG_GROUP("clear");
-    config.stencilTest = true;
-    config.stencilMask = 0xFF;
     config.depthTest = false;
     config.depthMask = GL_TRUE;
     config.clearColor = { 0.0f, 0.0f, 0.0f, 0.0f };
-    MBGL_CHECK_ERROR(glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));
+    MBGL_CHECK_ERROR(glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));
 }
 
 void Painter::setStrata(float value) {
     strata = value;
 }
 
-void Painter::prepareTile(const Tile& tile) {
-    const GLint ref = (GLint)tile.clip.reference.to_ulong();
-    const GLuint mask = (GLuint)tile.clip.mask.to_ulong();
-    config.stencilFunc = { GL_EQUAL, ref, mask };
-}
-
 void Painter::render(const Style& style, TransformState state_, const FrameData& frame_, const TimePoint& time) {
     state = state_;
     frame = frame_;
@@ -206,21 +194,17 @@ void Painter::render(const Style& style, TransformState state_, const FrameData&
     }
 
 
-    // - CLIPPING MASKS ----------------------------------------------------------------------------
-    // Draws the clipping masks to the stencil buffer.
+    // - MATRIX UPDATES ----------------------------------------------------------------------------
+    // Updates all matrices for all tiles.
     {
         MBGL_DEBUG_GROUP("clip");
 
         // Update all clipping IDs.
-        ClipIDGenerator generator;
         for (const auto& source : sources) {
-            generator.update(source->getLoadedTiles());
             source->updateMatrices(projMatrix, state);
         }
 
         clear();
-
-        drawClippingMasks(sources);
     }
 
     frameHistory.record(time, state.getNormalizedZoom());
@@ -291,7 +275,6 @@ void Painter::renderPass(RenderPass pass_,
             if (item.hasRenderPass(pass)) {
                 MBGL_DEBUG_GROUP(item.layer.id + " - " + std::string(item.tile->id));
                 setStrata(i * strataThickness);
-                prepareTile(*item.tile);
                 item.bucket->render(*this, item.layer, item.tile->id, item.tile->matrix);
             }
         } else {
@@ -460,7 +443,6 @@ void Painter::renderBackground(const StyleLayer &layer_desc) {
         backgroundArray.bind(*plainShader, backgroundBuffer, BUFFER_OFFSET(0));
     }
 
-    config.stencilTest = false;
     config.depthTest = true;
     config.depthRange = { strata + strata_epsilon, 1.0f };
     MBGL_CHECK_ERROR(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
diff --git a/src/mbgl/renderer/painter.hpp b/src/mbgl/renderer/painter.hpp
index 869aaa49cf..93c5959e01 100644
--- a/src/mbgl/renderer/painter.hpp
+++ b/src/mbgl/renderer/painter.hpp
@@ -130,9 +130,6 @@ public:
     // Configures the painter strata that is used for early z-culling of fragments.
     void setStrata(float strata);
 
-    void drawClippingMasks(const std::set<Source*>&);
-    void drawClippingMask(const mat4& matrix, const ClipID& clip);
-
     void resetFramebuffer();
     void bindFramebuffer();
     void pushFramebuffer();
@@ -154,8 +151,6 @@ private:
                     std::size_t i, int8_t iIncrement,
                     const float strataThickness);
 
-    void prepareTile(const Tile& tile);
-
     template <typename BucketProperties, typename StyleProperties>
     void renderSDF(SymbolBucket &bucket,
                    const TileID &id,
diff --git a/src/mbgl/renderer/painter_clipping.cpp b/src/mbgl/renderer/painter_clipping.cpp
deleted file mode 100644
index 332d2876f5..0000000000
--- a/src/mbgl/renderer/painter_clipping.cpp
+++ /dev/null
@@ -1,39 +0,0 @@
-#include <mbgl/renderer/painter.hpp>
-#include <mbgl/map/source.hpp>
-#include <mbgl/shader/plain_shader.hpp>
-#include <mbgl/util/clip_id.hpp>
-#include <mbgl/gl/debugging.hpp>
-
-using namespace mbgl;
-
-void Painter::drawClippingMasks(const std::set<Source*>& sources) {
-    MBGL_DEBUG_GROUP("clipping masks");
-
-    useProgram(plainShader->program);
-    config.stencilTest = true;
-    config.depthTest = true;
-    config.depthMask = GL_FALSE;
-    config.colorMask = { false, false, false, false };
-    config.depthRange = { 1.0f, 1.0f };
-
-    coveringPlainArray.bind(*plainShader, tileStencilBuffer, BUFFER_OFFSET(0));
-
-    for (const auto& source : sources) {
-        source->drawClippingMasks(*this);
-    }
-
-    config.depthTest = true;
-    config.colorMask = { true, true, true, true };
-    config.depthMask = GL_TRUE;
-    config.stencilMask = 0x0;
-}
-
-void Painter::drawClippingMask(const mat4& matrix, const ClipID &clip) {
-    plainShader->u_matrix = matrix;
-
-    const GLint ref = (GLint)(clip.reference.to_ulong());
-    const GLuint mask = (GLuint)(clip.mask.to_ulong());
-    config.stencilFunc = { GL_ALWAYS, ref, mask };
-    config.stencilMask = mask;
-    MBGL_CHECK_ERROR(glDrawArrays(GL_TRIANGLES, 0, (GLsizei)tileStencilBuffer.index()));
-}
diff --git a/src/mbgl/renderer/painter_debug.cpp b/src/mbgl/renderer/painter_debug.cpp
index f4f3a19cba..9c89cb1b96 100644
--- a/src/mbgl/renderer/painter_debug.cpp
+++ b/src/mbgl/renderer/painter_debug.cpp
@@ -13,7 +13,6 @@ void Painter::renderTileDebug(const Tile& tile) {
     MBGL_DEBUG_GROUP(std::string { "debug " } + std::string(tile.id));
     assert(tile.data);
     if (debug) {
-        prepareTile(tile);
         renderDebugText(tile.data->debugBucket, tile.matrix);
         renderDebugFrame(tile.matrix);
     }
@@ -53,7 +52,6 @@ void Painter::renderDebugFrame(const mat4 &matrix) {
     // but *don't* disable stencil test, as we want to clip the red tile border
     // to the tile viewport.
     config.depthTest = false;
-    config.stencilTest = true;
 
     useProgram(plainShader->program);
     plainShader->u_matrix = matrix;
diff --git a/src/mbgl/renderer/painter_fill.cpp b/src/mbgl/renderer/painter_fill.cpp
index 414ec2bbcb..6bc25b32d8 100644
--- a/src/mbgl/renderer/painter_fill.cpp
+++ b/src/mbgl/renderer/painter_fill.cpp
@@ -38,7 +38,6 @@ void Painter::renderFill(FillBucket& bucket, const StyleLayer &layer_desc, const
     bool outline = properties.antialias && !pattern && stroke_color != fill_color;
     bool fringeline = properties.antialias && !pattern && stroke_color == fill_color;
 
-    config.stencilTest = true;
     config.depthTest = true;
 
     // Because we're drawing top-to-bottom, and we update the stencil mask
diff --git a/src/mbgl/renderer/painter_line.cpp b/src/mbgl/renderer/painter_line.cpp
index f406c0d8f1..203ea0ddd6 100644
--- a/src/mbgl/renderer/painter_line.cpp
+++ b/src/mbgl/renderer/painter_line.cpp
@@ -18,7 +18,6 @@ void Painter::renderLine(LineBucket& bucket, const StyleLayer &layer_desc, const
     // Abort early.
     if (pass == RenderPass::Opaque) return;
 
-    config.stencilTest = true;
     config.depthTest = true;
     config.depthMask = GL_FALSE;
 
diff --git a/src/mbgl/renderer/painter_raster.cpp b/src/mbgl/renderer/painter_raster.cpp
index 2a8f8e7078..c3195eb4e7 100644
--- a/src/mbgl/renderer/painter_raster.cpp
+++ b/src/mbgl/renderer/painter_raster.cpp
@@ -22,7 +22,6 @@ void Painter::renderRaster(RasterBucket& bucket, const StyleLayer &layer_desc, c
         rasterShader->u_contrast_factor = contrastFactor(properties.contrast);
         rasterShader->u_spin_weights = spinWeights(properties.hue_rotate);
 
-        config.stencilTest = true;
         config.depthTest = true;
         config.depthRange = { strata + strata_epsilon, 1.0f };
         bucket.drawRaster(*rasterShader, tileStencilBuffer, coveringRasterArray);
diff --git a/src/mbgl/renderer/painter_symbol.cpp b/src/mbgl/renderer/painter_symbol.cpp
index 6d12768e2f..82cab0e38d 100644
--- a/src/mbgl/renderer/painter_symbol.cpp
+++ b/src/mbgl/renderer/painter_symbol.cpp
@@ -124,8 +124,6 @@ void Painter::renderSymbol(SymbolBucket &bucket, const StyleLayer &layer_desc, c
     config.depthMask = GL_FALSE;
 
     if (bucket.hasCollisionBoxData()) {
-        config.stencilTest = true;
-
         useProgram(collisionBoxShader->program);
         collisionBoxShader->u_matrix = matrix;
         collisionBoxShader->u_scale = std::pow(2, state.getNormalizedZoom() - id.z);
@@ -138,17 +136,6 @@ void Painter::renderSymbol(SymbolBucket &bucket, const StyleLayer &layer_desc, c
 
     }
 
-    // TODO remove the `|| true` when #1673 is implemented
-    const bool drawAcrossEdges = !(layout.text.allow_overlap || layout.icon.allow_overlap ||
-          layout.text.ignore_placement || layout.icon.ignore_placement) || true;
-
-    // Disable the stencil test so that labels aren't clipped to tile boundaries.
-    //
-    // Layers with features that may be drawn overlapping aren't clipped. These
-    // layers are sorted in the y direction, and to draw the correct ordering near
-    // tile edges the icons are included in both tiles and clipped when drawing.
-    config.stencilTest = drawAcrossEdges ? false : true;
-
     if (bucket.hasIconData()) {
         bool sdf = bucket.sdfIcons;