[core, ios, macos, android, node] Heatmap layer (#11046)

Co-Authored-By: Konstantin Käfer <mail@kkaefer.com>
Co-Authored-By: Anand Thakker <anandthakker@users.noreply.github.com>
Co-Authored-By: Minh Nguyễn <1ec5@users.noreply.github.com>

7 files changed, 123 insertions, 1 deletions

diff --git a/src/mbgl/programs/attributes.hpp b/src/mbgl/programs/attributes.hpp
index 5d7a6474cf..c677c84d5d 100644
--- a/src/mbgl/programs/attributes.hpp
+++ b/src/mbgl/programs/attributes.hpp
@@ -30,7 +30,7 @@ MBGL_DEFINE_ATTRIBUTE(int16_t, 2, a_anchor_pos);
 MBGL_DEFINE_ATTRIBUTE(uint16_t, 2, a_texture_pos);
 MBGL_DEFINE_ATTRIBUTE(int16_t,  4, a_normal_ed);
 MBGL_DEFINE_ATTRIBUTE(uint8_t, 1, a_fade_opacity);
-MBGL_DEFINE_ATTRIBUTE(uint8_t, 2, a_placed);                                        
+MBGL_DEFINE_ATTRIBUTE(uint8_t, 2, a_placed);
 
 template <typename T, std::size_t N>
 struct a_data {
@@ -142,6 +142,11 @@ struct a_halo_blur {
     using Type = gl::Attribute<float, 1>;
 };
 
+struct a_weight {
+    static auto name() { return "a_weight"; }
+    using Type = gl::Attribute<float, 1>;
+};
+
 } // namespace attributes
 
 struct PositionOnlyLayoutAttributes : gl::Attributes<
diff --git a/src/mbgl/programs/heatmap_program.cpp b/src/mbgl/programs/heatmap_program.cpp
new file mode 100644
index 0000000000..67f84fbd52
--- /dev/null
+++ b/src/mbgl/programs/heatmap_program.cpp
@@ -0,0 +1,7 @@
+#include <mbgl/programs/heatmap_program.hpp>
+
+namespace mbgl {
+
+static_assert(sizeof(HeatmapLayoutVertex) == 4, "expected HeatmapLayoutVertex size");
+
+} // namespace mbgl
diff --git a/src/mbgl/programs/heatmap_program.hpp b/src/mbgl/programs/heatmap_program.hpp
new file mode 100644
index 0000000000..2d9b80404f
--- /dev/null
+++ b/src/mbgl/programs/heatmap_program.hpp
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <mbgl/programs/program.hpp>
+#include <mbgl/programs/attributes.hpp>
+#include <mbgl/programs/uniforms.hpp>
+#include <mbgl/shaders/heatmap.hpp>
+#include <mbgl/util/geometry.hpp>
+#include <mbgl/style/layers/heatmap_layer_properties.hpp>
+
+namespace mbgl {
+
+namespace uniforms {
+MBGL_DEFINE_UNIFORM_SCALAR(float, u_intensity);
+} // namespace uniforms
+
+class HeatmapProgram : public Program<
+    shaders::heatmap,
+    gl::Triangle,
+    gl::Attributes<
+        attributes::a_pos>,
+    gl::Uniforms<
+        uniforms::u_intensity,
+        uniforms::u_matrix,
+        uniforms::heatmap::u_extrude_scale>,
+    style::HeatmapPaintProperties>
+{
+public:
+    using Program::Program;
+
+    /*
+     * @param {number} x vertex position
+     * @param {number} y vertex position
+     * @param {number} ex extrude normal
+     * @param {number} ey extrude normal
+     */
+    static LayoutVertex vertex(Point<int16_t> p, float ex, float ey) {
+        return LayoutVertex {
+            {{
+                static_cast<int16_t>((p.x * 2) + ((ex + 1) / 2)),
+                static_cast<int16_t>((p.y * 2) + ((ey + 1) / 2))
+            }}
+        };
+    }
+};
+
+using HeatmapLayoutVertex = HeatmapProgram::LayoutVertex;
+using HeatmapAttributes = HeatmapProgram::Attributes;
+
+} // namespace mbgl
diff --git a/src/mbgl/programs/heatmap_texture_program.cpp b/src/mbgl/programs/heatmap_texture_program.cpp
new file mode 100644
index 0000000000..3b0e24eab8
--- /dev/null
+++ b/src/mbgl/programs/heatmap_texture_program.cpp
@@ -0,0 +1,7 @@
+#include <mbgl/programs/heatmap_texture_program.hpp>
+
+namespace mbgl {
+
+static_assert(sizeof(HeatmapTextureLayoutVertex) == 4, "expected HeatmapTextureLayoutVertex size");
+
+} // namespace mbgl
diff --git a/src/mbgl/programs/heatmap_texture_program.hpp b/src/mbgl/programs/heatmap_texture_program.hpp
new file mode 100644
index 0000000000..7afe8060d0
--- /dev/null
+++ b/src/mbgl/programs/heatmap_texture_program.hpp
@@ -0,0 +1,43 @@
+#pragma once
+
+#include <mbgl/programs/program.hpp>
+#include <mbgl/programs/attributes.hpp>
+#include <mbgl/programs/uniforms.hpp>
+#include <mbgl/shaders/heatmap_texture.hpp>
+#include <mbgl/style/properties.hpp>
+#include <mbgl/util/geometry.hpp>
+
+namespace mbgl {
+
+namespace uniforms {
+MBGL_DEFINE_UNIFORM_SCALAR(gl::TextureUnit, u_color_ramp);
+} // namespace uniforms
+
+class HeatmapTextureProgram : public Program<
+    shaders::heatmap_texture,
+    gl::Triangle,
+    gl::Attributes<attributes::a_pos>,
+    gl::Uniforms<
+        uniforms::u_matrix,
+        uniforms::u_world,
+        uniforms::u_image,
+        uniforms::u_color_ramp,
+        uniforms::u_opacity>,
+    style::Properties<>> {
+public:
+    using Program::Program;
+
+    static LayoutVertex layoutVertex(Point<int16_t> p) {
+        return LayoutVertex{
+            {{
+                p.x,
+                p.y
+            }}
+        };
+    }
+};
+
+using HeatmapTextureLayoutVertex = HeatmapTextureProgram::LayoutVertex;
+using HeatmapTextureAttributes = HeatmapTextureProgram::Attributes;
+
+} // namespace mbgl
diff --git a/src/mbgl/programs/programs.hpp b/src/mbgl/programs/programs.hpp
index f533a6f633..b703323d9c 100644
--- a/src/mbgl/programs/programs.hpp
+++ b/src/mbgl/programs/programs.hpp
@@ -6,6 +6,8 @@
 #include <mbgl/programs/extrusion_texture_program.hpp>
 #include <mbgl/programs/fill_program.hpp>
 #include <mbgl/programs/fill_extrusion_program.hpp>
+#include <mbgl/programs/heatmap_program.hpp>
+#include <mbgl/programs/heatmap_texture_program.hpp>
 #include <mbgl/programs/hillshade_program.hpp>
 #include <mbgl/programs/hillshade_prepare_program.hpp>
 #include <mbgl/programs/line_program.hpp>
@@ -30,6 +32,8 @@ public:
           fillPattern(context, programParameters),
           fillOutline(context, programParameters),
           fillOutlinePattern(context, programParameters),
+          heatmap(context, programParameters),
+          heatmapTexture(context, programParameters),
           hillshade(context, programParameters),
           hillshadePrepare(context, programParameters),
           line(context, programParameters),
@@ -55,6 +59,8 @@ public:
     ProgramMap<FillPatternProgram> fillPattern;
     ProgramMap<FillOutlineProgram> fillOutline;
     ProgramMap<FillOutlinePatternProgram> fillOutlinePattern;
+    ProgramMap<HeatmapProgram> heatmap;
+    HeatmapTextureProgram heatmapTexture;
     HillshadeProgram hillshade;
     HillshadePrepareProgram hillshadePrepare;
     ProgramMap<LineProgram> line;
diff --git a/src/mbgl/programs/uniforms.hpp b/src/mbgl/programs/uniforms.hpp
index 107c084918..071a27c808 100644
--- a/src/mbgl/programs/uniforms.hpp
+++ b/src/mbgl/programs/uniforms.hpp
@@ -37,9 +37,14 @@ MBGL_DEFINE_UNIFORM_SCALAR(Size, u_texsize);
 MBGL_DEFINE_UNIFORM_SCALAR(bool, u_pitch_with_map);
 MBGL_DEFINE_UNIFORM_SCALAR(float, u_camera_to_center_distance);
 MBGL_DEFINE_UNIFORM_SCALAR(float, u_fade_change);
+MBGL_DEFINE_UNIFORM_SCALAR(float, u_weight);
 
 MBGL_DEFINE_UNIFORM_VECTOR(float, 2, u_extrude_scale);
 
+namespace heatmap {
+MBGL_DEFINE_UNIFORM_SCALAR(float, u_extrude_scale);
+} // namespace heatmap
+
 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);