1 files changed, 143 insertions, 0 deletions
diff --git a/src/mbgl/shader/symbol_uniforms.cpp b/src/mbgl/shader/symbol_uniforms.cpp
new file mode 100644
index 0000000000..cd9f33de71
--- /dev/null
+++ b/src/mbgl/shader/symbol_uniforms.cpp
@@ -0,0 +1,143 @@
+#include <mbgl/shader/symbol_uniforms.hpp>
+#include <mbgl/renderer/render_tile.hpp>
+#include <mbgl/map/transform_state.hpp>
+#include <mbgl/style/layers/symbol_layer_impl.hpp>
+
+namespace mbgl {
+
+using namespace style;
+
+template <class Values, class...Args>
+Values makeValues(const style::SymbolPropertyValues& values,
+                  const std::array<uint16_t, 2>& texsize,
+                  const std::array<float, 2>& pixelsToGLUnits,
+                  const RenderTile& tile,
+                  const TransformState& state,
+                  Args&&... args) {
+    std::array<float, 2> extrudeScale;
+
+    const float scale = values.paintSize / values.sdfScale;
+    if (values.pitchAlignment == AlignmentType::Map) {
+        extrudeScale.fill(tile.id.pixelsToTileUnits(1, state.getZoom()) * scale);
+    } else {
+        extrudeScale = {{
+            pixelsToGLUnits[0] * scale * state.getAltitude(),
+            pixelsToGLUnits[1] * scale * state.getAltitude()
+        }};
+    }
+
+    // adjust min/max zooms for variable font sies
+    float zoomAdjust = std::log(values.paintSize / values.layoutSize) / std::log(2);
+
+    return Values {
+        tile.translatedMatrix(values.translate,
+                              values.translateAnchor,
+                              state),
+        values.opacity,
+        extrudeScale,
+        std::array<float, 2> {{ texsize[0] / 4.0f, texsize[1] / 4.0f }},
+        (state.getZoom() - zoomAdjust) * 10.0f,
+        values.rotationAlignment == AlignmentType::Map,
+        0,
+        1,
+        std::forward<Args>(args)...
+    };
+}
+
+SymbolIconUniforms::Values
+SymbolIconUniforms::values(const style::SymbolPropertyValues& values,
+                           const std::array<uint16_t, 2>& texsize,
+                           const std::array<float, 2>& pixelsToGLUnits,
+                           const RenderTile& tile,
+                           const TransformState& state)
+{
+    return makeValues<SymbolIconUniforms::Values>(
+        values,
+        texsize,
+        pixelsToGLUnits,
+        tile,
+        state
+    );
+}
+
+static SymbolSDFUniforms::Values makeSDFValues(const style::SymbolPropertyValues& values,
+                                               const std::array<uint16_t, 2>& texsize,
+                                               const std::array<float, 2>& pixelsToGLUnits,
+                                               const RenderTile& tile,
+                                               const TransformState& state,
+                                               float pixelRatio,
+                                               Color color,
+                                               float buffer,
+                                               float gammaAdjust)
+{
+    // The default gamma value has to be adjust for the current pixelratio so that we're not
+    // drawing blurry font on retina screens.
+    const float gammaBase = 0.105 * values.sdfScale / values.paintSize / pixelRatio;
+    const float gammaScale = values.pitchAlignment == AlignmentType::Map
+        ? 1.0 / std::cos(state.getPitch())
+        : 1.0;
+
+    return makeValues<SymbolSDFUniforms::Values>(
+        values,
+        texsize,
+        pixelsToGLUnits,
+        tile,
+        state,
+        color,
+        buffer,
+        (gammaBase + gammaAdjust) * gammaScale,
+        state.getPitch(),
+        -1.0f * state.getAngle(),
+        (state.getSize().width * 1.0f) / (state.getSize().height * 1.0f),
+        values.pitchAlignment == AlignmentType::Map
+    );
+}
+
+SymbolSDFUniforms::Values
+SymbolSDFUniforms::haloValues(const style::SymbolPropertyValues& values,
+                              const std::array<uint16_t, 2>& texsize,
+                              const std::array<float, 2>& pixelsToGLUnits,
+                              const RenderTile& tile,
+                              const TransformState& state,
+                              float pixelRatio)
+{
+    const float scale = values.paintSize / values.sdfScale;
+    const float sdfPx = 8.0f;
+    const float blurOffset = 1.19f;
+    const float haloOffset = 6.0f;
+
+    return makeSDFValues(
+        values,
+        texsize,
+        pixelsToGLUnits,
+        tile,
+        state,
+        pixelRatio,
+        values.haloColor,
+        (haloOffset - values.haloWidth / scale) / sdfPx,
+        values.haloBlur * blurOffset / scale / sdfPx
+    );
+}
+
+SymbolSDFUniforms::Values
+SymbolSDFUniforms::foregroundValues(const style::SymbolPropertyValues& values,
+                                    const std::array<uint16_t, 2>& texsize,
+                                    const std::array<float, 2>& pixelsToGLUnits,
+                                    const RenderTile& tile,
+                                    const TransformState& state,
+                                    float pixelRatio)
+{
+    return makeSDFValues(
+        values,
+        texsize,
+        pixelsToGLUnits,
+        tile,
+        state,
+        pixelRatio,
+        values.color,
+        (256.0f - 64.0f) / 256.0f,
+        0
+    );
+}
+
+} // namespace mbgl