[core] Simplify and fix sprite atlas coordinate calculations

* Always return image metrics exclusive of padding
* Work with integer coordinates whenever possible
* Eliminate redundant SpriteAtlasElement members
* Fix asymmetric re-padding in getIconQuad when pixelRatio != 1
* Add explanatory comments

4 files changed, 24 insertions, 24 deletions

diff --git a/src/mbgl/programs/fill_extrusion_program.cpp b/src/mbgl/programs/fill_extrusion_program.cpp
index 1b0f483b1a..3f85d83788 100644
--- a/src/mbgl/programs/fill_extrusion_program.cpp
+++ b/src/mbgl/programs/fill_extrusion_program.cpp
@@ -59,12 +59,12 @@ FillExtrusionPatternUniforms::values(mat4 matrix,
 
     return FillExtrusionPatternUniforms::Values{
         uniforms::u_matrix::Value{ matrix },
-        uniforms::u_pattern_tl_a::Value{ a.tl },
-        uniforms::u_pattern_br_a::Value{ a.br },
-        uniforms::u_pattern_tl_b::Value{ b.tl },
-        uniforms::u_pattern_br_b::Value{ b.br },
-        uniforms::u_pattern_size_a::Value{ a.size },
-        uniforms::u_pattern_size_b::Value{ b.size },
+        uniforms::u_pattern_tl_a::Value{ a.tl() },
+        uniforms::u_pattern_br_a::Value{ a.br() },
+        uniforms::u_pattern_tl_b::Value{ b.tl() },
+        uniforms::u_pattern_br_b::Value{ b.br() },
+        uniforms::u_pattern_size_a::Value{ a.displaySize() },
+        uniforms::u_pattern_size_b::Value{ b.displaySize() },
         uniforms::u_scale_a::Value{ fading.fromScale },
         uniforms::u_scale_b::Value{ fading.toScale },
         uniforms::u_texsize::Value{ atlasSize },
diff --git a/src/mbgl/programs/fill_program.cpp b/src/mbgl/programs/fill_program.cpp
index 13f7b00e35..6c19e503ce 100644
--- a/src/mbgl/programs/fill_program.cpp
+++ b/src/mbgl/programs/fill_program.cpp
@@ -28,12 +28,12 @@ FillPatternUniforms::values(mat4 matrix,
         uniforms::u_matrix::Value{ matrix },
         uniforms::u_world::Value{ framebufferSize },
         uniforms::u_texsize::Value{ atlasSize },
-        uniforms::u_pattern_tl_a::Value{ a.tl },
-        uniforms::u_pattern_br_a::Value{ a.br },
-        uniforms::u_pattern_tl_b::Value{ b.tl },
-        uniforms::u_pattern_br_b::Value{ b.br },
-        uniforms::u_pattern_size_a::Value{ a.size },
-        uniforms::u_pattern_size_b::Value{ b.size },
+        uniforms::u_pattern_tl_a::Value{ a.tl() },
+        uniforms::u_pattern_br_a::Value{ a.br() },
+        uniforms::u_pattern_tl_b::Value{ b.tl() },
+        uniforms::u_pattern_br_b::Value{ b.br() },
+        uniforms::u_pattern_size_a::Value{ a.displaySize() },
+        uniforms::u_pattern_size_b::Value{ b.displaySize() },
         uniforms::u_scale_a::Value{ fading.fromScale },
         uniforms::u_scale_b::Value{ fading.toScale },
         uniforms::u_mix::Value{ fading.t },
diff --git a/src/mbgl/programs/line_program.cpp b/src/mbgl/programs/line_program.cpp
index 1e296963f2..2c65cb74ed 100644
--- a/src/mbgl/programs/line_program.cpp
+++ b/src/mbgl/programs/line_program.cpp
@@ -92,13 +92,13 @@ LinePatternProgram::uniformValues(const LinePaintProperties::PossiblyEvaluated&
                                   const SpriteAtlasElement& posA,
                                   const SpriteAtlasElement& posB) {
      std::array<float, 2> sizeA {{
-         tile.id.pixelsToTileUnits(posA.size[0] * properties.get<LinePattern>().fromScale, state.getIntegerZoom()),
-         posA.size[1]
+         tile.id.pixelsToTileUnits(posA.displaySize()[0] * properties.get<LinePattern>().fromScale, state.getIntegerZoom()),
+         posA.displaySize()[1]
      }};
 
      std::array<float, 2> sizeB {{
-         tile.id.pixelsToTileUnits(posB.size[0] * properties.get<LinePattern>().toScale, state.getIntegerZoom()),
-         posB.size[1]
+         tile.id.pixelsToTileUnits(posB.displaySize()[0] * properties.get<LinePattern>().toScale, state.getIntegerZoom()),
+         posB.displaySize()[1]
      }};
 
     return makeValues<LinePatternProgram::UniformValues>(
@@ -106,10 +106,10 @@ LinePatternProgram::uniformValues(const LinePaintProperties::PossiblyEvaluated&
         tile,
         state,
         pixelsToGLUnits,
-        uniforms::u_pattern_tl_a::Value{ posA.tl },
-        uniforms::u_pattern_br_a::Value{ posA.br },
-        uniforms::u_pattern_tl_b::Value{ posB.tl },
-        uniforms::u_pattern_br_b::Value{ posB.br },
+        uniforms::u_pattern_tl_a::Value{ posA.tl() },
+        uniforms::u_pattern_br_a::Value{ posA.br() },
+        uniforms::u_pattern_tl_b::Value{ posB.tl() },
+        uniforms::u_pattern_br_b::Value{ posB.br() },
         uniforms::u_pattern_size_a::Value{ sizeA },
         uniforms::u_pattern_size_b::Value{ sizeB },
         uniforms::u_texsize::Value{ atlasSize },
diff --git a/src/mbgl/programs/uniforms.hpp b/src/mbgl/programs/uniforms.hpp
index a2bfe396b1..78ac09942c 100644
--- a/src/mbgl/programs/uniforms.hpp
+++ b/src/mbgl/programs/uniforms.hpp
@@ -22,10 +22,10 @@ MBGL_DEFINE_UNIFORM_SCALAR(Size, u_texsize);
 
 MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_extrude_scale);
 
-MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pattern_tl_a);
-MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pattern_br_a);
-MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pattern_tl_b);
-MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pattern_br_b);
+MBGL_DEFINE_UNIFORM_VECTOR(uint16_t, 2, u_pattern_tl_a);
+MBGL_DEFINE_UNIFORM_VECTOR(uint16_t, 2, u_pattern_br_a);
+MBGL_DEFINE_UNIFORM_VECTOR(uint16_t, 2, u_pattern_tl_b);
+MBGL_DEFINE_UNIFORM_VECTOR(uint16_t, 2, u_pattern_br_b);
 MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pattern_size_a);
 MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pattern_size_b);
 MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_pixel_coord_upper);