Hash uniform name strings

src/base/hash.h

@@ -6,17 +6,15 @@
 
 namespace base {
 
-// Compile-time string hashing function.
 template <size_t N>
-constexpr inline size_t Hash(const char (&str)[N], size_t Len = N - 1) {
+constexpr inline size_t KR2Hash(const char (&str)[N], size_t Len = N - 1) {
   size_t hash_value = 0;
   for (int i = 0; str[i] != '\0'; ++i)
     hash_value = str[i] + 31 * hash_value;
   return hash_value;
 }
 
-// The same hashing function for run-time.
-inline size_t Hash(const std::string& str) {
+inline size_t KR2Hash(const std::string& str) {
   size_t hash_value = 0;
   for (std::string::value_type c : str)
     hash_value = c + 31 * hash_value;

src/engine/renderer/opengl/renderer_opengl.cc

@@ -5,6 +5,7 @@
 #include <sstream>
 #include <unordered_set>
 
+#include "base/hash.h"
 #include "base/log.h"
 #include "base/vecmath.h"
 #include "engine/asset/image.h"
@@ -615,10 +616,11 @@ bool RendererOpenGL::BindAttributeLocation(GLuint id,
 GLint RendererOpenGL::GetUniformLocation(
     GLuint id,
     const std::string& name,
-    std::vector<std::pair<std::string, GLuint>>& uniforms) {
+    std::vector<std::pair<size_t, GLuint>>& uniforms) {
   // Check if we've encountered this uniform before.
+  auto hash = KR2Hash(name);
   auto it = std::find_if(uniforms.begin(), uniforms.end(),
-                         [&](auto& r) { return name == std::get<0>(r); });
+                         [&](auto& r) { return hash == std::get<0>(r); });
   GLint index;
   if (it != uniforms.end()) {
     // Yes, we already have the mapping.
@@ -626,11 +628,16 @@ GLint RendererOpenGL::GetUniformLocation(
   } else {
     // No, ask the driver for the mapping and save it.
     index = glGetUniformLocation(id, name.c_str());
-    if (index >= 0)
-      uniforms.emplace_back(std::make_pair(name, index));
-    else
+    if (index >= 0) {
+      DCHECK(std::find_if(uniforms.begin(), uniforms.end(),
+                          [&](auto& r) { return hash == std::get<0>(r); }) ==
+             uniforms.end())
+          << "Hash collision";
+      uniforms.emplace_back(std::make_pair(hash, index));
+    } else {
       LOG(0) << "Cannot find uniform " << name.c_str() << " (shader: " << id
              << ")";
+    }
   }
   return index;
 }

src/engine/renderer/opengl/renderer_opengl.h

@@ -95,7 +95,10 @@ class RendererOpenGL final : public Renderer {
 
   struct ShaderOpenGL {
     GLuint id = 0;
-    std::vector<std::pair<std::string, GLuint>> uniforms;
+    std::vector<std::pair<size_t,  // Uniform name hash
+                          GLuint   // Uniform index
+                          >>
+        uniforms;
     bool enable_depth_test = false;
   };
 
@@ -139,10 +142,9 @@ class RendererOpenGL final : public Renderer {
                          std::vector<GeometryOpenGL::Element>& vertex_layout);
   GLuint CreateShader(const char* source, GLenum type);
   bool BindAttributeLocation(GLuint id, const VertexDescription& vd);
-  GLint GetUniformLocation(
-      GLuint id,
-      const std::string& name,
-      std::vector<std::pair<std::string, GLuint>>& uniforms);
+  GLint GetUniformLocation(GLuint id,
+                           const std::string& name,
+                           std::vector<std::pair<size_t, GLuint>>& uniforms);
 };
 
 }  // namespace eng

src/engine/renderer/vulkan/renderer_vulkan.cc

@@ -5,6 +5,7 @@
 #include <sstream>
 #include <utility>
 
+#include "base/hash.h"
 #include "base/log.h"
 #include "base/vecmath.h"
 #include "engine/asset/image.h"
@@ -1876,12 +1877,12 @@ bool RendererVulkan::CreatePipelineLayout(
 
       size_t offset = 0;
       for (uint32_t j = 0; j < pconstants_vertex[0]->member_count; j++) {
-        DCHECK(std::find_if(shader.variables.begin(), shader.variables.end(),
-                            [&](auto& r) {
-                              return pconstants_vertex[0]->members[j].name ==
-                                     std::get<0>(r);
-                            }) == shader.variables.end())
-            << "Duplicate uniform name";
+        DCHECK(std::find_if(
+                   shader.variables.begin(), shader.variables.end(),
+                   [hash = KR2Hash(pconstants_vertex[0]->members[j].name)](
+                       auto& r) { return hash == std::get<0>(r); }) ==
+               shader.variables.end())
+            << "Hash collision";
 
         DLOG(0) << __func__
                 << " name: " << pconstants_vertex[0]->members[j].name
@@ -1890,7 +1891,7 @@ bool RendererVulkan::CreatePipelineLayout(
                 << pconstants_vertex[0]->members[j].padded_size;
 
         shader.variables.emplace_back(
-            std::make_tuple(pconstants_vertex[0]->members[j].name,
+            std::make_tuple(KR2Hash(pconstants_vertex[0]->members[j].name),
                             pconstants_vertex[0]->members[j].size, offset));
         offset += pconstants_vertex[0]->members[j].padded_size;
       }
@@ -2040,8 +2041,9 @@ template <typename T>
 bool RendererVulkan::SetUniformInternal(ShaderVulkan& shader,
                                         const std::string& name,
                                         T val) {
+  auto hash = KR2Hash(name);
   auto it = std::find_if(shader.variables.begin(), shader.variables.end(),
-                         [&](auto& r) { return name == std::get<0>(r); });
+                         [&](auto& r) { return hash == std::get<0>(r); });
   if (it == shader.variables.end()) {
     DLOG(0) << "No variable found with name " << name;
     return false;

src/engine/renderer/vulkan/renderer_vulkan.h

@@ -106,7 +106,11 @@ class RendererVulkan final : public Renderer {
   };
 
   struct ShaderVulkan {
-    std::vector<std::tuple<std::string, size_t, size_t>> variables;
+    std::vector<std::tuple<size_t,  // Variable name hash
+                           size_t,  // Variable size
+                           size_t   // Push constant offset
+                           >>
+        variables;
     std::unique_ptr<char[]> push_constants;
     size_t push_constants_size = 0;
     std::vector<std::string> sampler_uniform_names;