shader auto reload

src/shader.cpp

@@ -13,6 +13,10 @@ std::string Shader::read(const std::string& path)
     std::string ret;
     if (a.open(path.c_str()))
     {
+        struct stat tmp_info;
+        if (stat(path.c_str(), &tmp_info) == 0)
+            m_deps[path] = tmp_info;
+
         std::regex reg_include(R"!(#include "([^"]+)")!");
         std::string data((char*)a.read_all(), a.m_len);
 
@@ -105,18 +109,46 @@ bool Shader::load(const std::string& path)
     {
         *sections["vertex"] = SHADER_VERSION + *sections["vertex"];
         *sections["fragment"] = SHADER_VERSION + *sections["fragment"];
-        return create(sections["vertex"]->c_str(), sections["fragment"]->c_str());
+        if (create(sections["vertex"]->c_str(), sections["fragment"]->c_str()))
+        {
+            m_path = path;
+            return true;
+        }
     }
     else
     {
         LOG("could not find [[vertex]] and [[fragment]] sections on %s", path.c_str());
     }
 
-    m_path = path;
-
     return false;
 }
 
+bool Shader::reload()
+{
+    if (m_path.empty())
+        return false;
+
+    bool dirty = false;
+    struct stat tmp_info;
+    for (auto& d : m_deps)
+    {
+        if (stat(d.first.c_str(), &tmp_info) != 0)
+            continue;
+        if (tmp_info.st_mtime > d.second.st_mtime)
+        {
+            d.second = tmp_info;
+            dirty = true;
+        }
+    }
+
+    if (dirty)
+    {
+        LOG("reload shader %s", m_path.c_str());
+        destroy();
+        return load(m_path);
+    }
+}
+
 bool Shader::create(const char* vertex, const char* fragment)
 {
     GLint status;
@@ -136,7 +168,7 @@ bool Shader::create(const char* vertex, const char* fragment)
     glGetShaderInfoLog(vs, sizeof(infolog), &infolen, infolog);
     if (infolen > 0)
     {
-        LOG("\nVERTEX SHADER:");
+        LOG("\nVERTEX SHADER: %s", m_path.c_str());
         parse_error(infolog, vertex);
     }
     if (status == 0)
@@ -158,7 +190,7 @@ bool Shader::create(const char* vertex, const char* fragment)
     glGetShaderInfoLog(fs, sizeof(infolog), &infolen, infolog);
     if (infolen > 0)
     {
-        LOG("\nFRAGMENT SHADER:");
+        LOG("\nFRAGMENT SHADER: %s", m_path.c_str());
         parse_error(infolog, fragment);
     }
     if (status == 0)
@@ -200,7 +232,7 @@ bool Shader::create(const char* vertex, const char* fragment)
     glGetProgramiv(ps, GL_LINK_STATUS, &status);
     glGetProgramInfoLog(ps, sizeof(infolog), &infolen, infolog);
     if (infolen > 0)
-        LOG("LINK SHADER:\n%s", infolog);
+        LOG("LINK SHADER: %s\n%s", m_path.c_str(), infolog);
     if (status == 0)
     {
         glDeleteProgram(ps);
@@ -228,6 +260,18 @@ bool Shader::create(const char* vertex, const char* fragment)
     
     return true;
 }
+
+void Shader::destroy()
+{
+    if (prog)
+    {
+        glUseProgram(0);
+        glDeleteProgram(prog);
+        prog = 0;
+    }
+    m_umap.clear();
+}
+
 void Shader::use()
 {
     glUseProgram(prog);
@@ -282,6 +326,14 @@ bool ShaderManager::load(kShader id, const std::string& path)
     return m_shaders[id].load(path);
 }
 
+bool ShaderManager::reload()
+{
+    bool success = true;
+    for (auto& s : m_shaders)
+        success &= s.second.reload();
+    return success;
+}
+
 bool ShaderManager::create(kShader id, const char* vertex, const char* fragment)
 {
     m_shaders[id].name = id;