[core] cleanup ProgramParameters

cmake/core-files.cmake

@@ -148,6 +148,7 @@ set(MBGL_CORE_FILES
     src/mbgl/programs/line_program.cpp
     src/mbgl/programs/line_program.hpp
     src/mbgl/programs/program.hpp
+    src/mbgl/programs/program_parameters.cpp
     src/mbgl/programs/program_parameters.hpp
     src/mbgl/programs/programs.hpp
     src/mbgl/programs/raster_program.cpp

src/mbgl/gl/program.hpp

@@ -55,11 +55,11 @@ class Program {
                 shaders::vertexSource(programParameters, vertexSource_);
             const std::string fragmentSource =
                 shaders::fragmentSource(programParameters, fragmentSource_);
-            const std::string cachePath =
-                shaders::programCachePath(programParameters, name);
             const std::string identifier =
                 shaders::programIdentifier(vertexSource, fragmentSource_);
 
+            const std::string cachePath = programParameters.cachePath(name);
+
             try {
                 if (auto cachedBinaryProgram = util::readFile(cachePath)) {
                     const BinaryProgram binaryProgram(std::move(*cachedBinaryProgram));

src/mbgl/programs/program_parameters.cpp

@@ -0,0 +1,32 @@
+#include <mbgl/programs/program_parameters.hpp>
+
+#include <iomanip>
+#include <sstream>
+
+namespace mbgl {
+
+ProgramParameters::ProgramParameters(const float pixelRatio,
+                                     const bool overdraw,
+                                     std::string cacheDir_)
+    : defines([&] {
+          std::ostringstream ss;
+          ss.imbue(std::locale("C"));
+          ss.setf(std::ios_base::showpoint);
+          ss << "#define DEVICE_PIXEL_RATIO " << pixelRatio << std::endl;
+          if (overdraw) {
+              ss << "#define OVERDRAW_INSPECTOR" << std::endl;
+          }
+          return ss.str();
+      }()),
+      hash(std::hash<std::string>()(defines)),
+      cacheDir(std::move(cacheDir_)) {
+}
+
+std::string ProgramParameters::cachePath(const char* name) const {
+    std::ostringstream ss;
+    ss << cacheDir << "/com.mapbox.gl.shader." << name << "." << std::setfill('0')
+       << std::setw(sizeof(size_t) * 2) << std::hex << hash << ".pbf";
+    return ss.str();
+}
+
+} // namespace mbgl

src/mbgl/programs/program_parameters.hpp

@@ -7,16 +7,15 @@ namespace mbgl {
 
 class ProgramParameters {
 public:
-    ProgramParameters(float pixelRatio_ = 1.0,
-                      bool overdraw_ = false,
-                      std::string cacheDir_ = "")
-        : pixelRatio(pixelRatio_), overdraw(overdraw_), cacheDir(std::move(cacheDir_)) {
-    }
+    ProgramParameters(float pixelRatio, bool overdraw, std::string cacheDir);
 
-    const float pixelRatio;
-    const bool overdraw;
+    const std::string defines;
+
+    std::string cachePath(const char* name) const;
+
+private:
+    const std::size_t hash;
     const std::string cacheDir;
 };
 
 } // namespace mbgl
-

src/mbgl/programs/programs.hpp

@@ -31,8 +31,8 @@ class Programs {
           symbolIcon(context, programParameters),
           symbolIconSDF(context, programParameters),
           symbolGlyph(context, programParameters),
-          debug(context, ProgramParameters(programParameters.pixelRatio, false, programParameters.cacheDir)),
-          collisionBox(context, ProgramParameters(programParameters.pixelRatio, false, programParameters.cacheDir)) {
+          debug(context, programParameters),
+          collisionBox(context, programParameters) {
     }
 
     CircleProgram circle;

src/mbgl/shaders/shaders.cpp

@@ -9,30 +9,12 @@
 namespace mbgl {
 namespace shaders {
 
-static std::string pixelRatioDefine(const ProgramParameters& parameters) {
-    std::ostringstream pixelRatioSS;
-    pixelRatioSS.imbue(std::locale("C"));
-    pixelRatioSS.setf(std::ios_base::showpoint);
-    pixelRatioSS << parameters.pixelRatio;
-    return std::string("#define DEVICE_PIXEL_RATIO ") + pixelRatioSS.str() + "\n";
-}
-
 std::string fragmentSource(const ProgramParameters& parameters, const char* fragmentSource) {
-    std::string source = pixelRatioDefine(parameters) + fragmentPrelude + fragmentSource;
-    if (parameters.overdraw) {
-        assert(source.find("#ifdef OVERDRAW_INSPECTOR") != std::string::npos);
-        source.replace(source.find_first_of('\n'), 1, "\n#define OVERDRAW_INSPECTOR\n");
-    }
-    return source;
+    return parameters.defines + fragmentPrelude + fragmentSource;
 }
 
 std::string vertexSource(const ProgramParameters& parameters, const char* vertexSource) {
-    return pixelRatioDefine(parameters) + vertexPrelude + vertexSource;
-}
-
-std::string programCachePath(const ProgramParameters& parameters, const char* name) {
-    return parameters.cacheDir + "/com.mapbox.gl.shader." + name +
-           (parameters.overdraw ? ".overdraw.pbf" : ".pbf");
+    return parameters.defines + vertexPrelude + vertexSource;
 }
 
 std::string programIdentifier(const std::string& vertexSource, const std::string& fragmentSource) {

src/mbgl/shaders/shaders.hpp

@@ -10,7 +10,6 @@ namespace shaders {
 
 std::string fragmentSource(const ProgramParameters&, const char* fragmentSource);
 std::string vertexSource(const ProgramParameters&, const char* vertexSource);
-std::string programCachePath(const ProgramParameters&, const char* name);
 std::string programIdentifier(const std::string& vertexSource, const std::string& fragmentSource);
 
 } // namespace shaders