Implemented ShaderProgramBuilder

source/shader/CMakeLists.txt

@@ -0,0 +1,14 @@
+project(UglyShaderLib)
+
+add_library(${PROJECT_NAME}
+    ./src/ShaderProgramBuilder.cpp
+)
+
+target_include_directories(${PROJECT_NAME}
+    PUBLIC ./include
+    PRIVATE ./src
+)
+
+target_link_libraries(${PROJECT_NAME}
+    GLEW::GLEW
+)

source/shader/include/ShaderProgramBuilder.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <stdexcept>
+
+#include <GL/glew.h>
+
+namespace ugly{
+
+class ShaderProgramBuilder {
+public:
+    class Error: public std::runtime_error{
+    public:
+        using std::runtime_error::runtime_error;
+    };
+
+public:
+    ShaderProgramBuilder();
+    ~ShaderProgramBuilder();
+    void reset();
+    ShaderProgramBuilder &attachFromMemory(GLenum type, const GLchar *string, GLint length = 0);
+    ShaderProgramBuilder &attachFromFile(GLenum type, const char *filename);
+    GLuint link();
+
+private:
+    GLuint mProgram;
+};
+
+}

source/shader/src/ShaderProgramBuilder.cpp

@@ -0,0 +1,73 @@
+#include "ShaderProgramBuilder.hpp"
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <utility>
+
+
+ugly::ShaderProgramBuilder::ShaderProgramBuilder():
+    mProgram{glCreateProgram()} {
+}
+
+
+ugly::ShaderProgramBuilder::~ShaderProgramBuilder() {
+    if(mProgram != 0) {
+        glDeleteProgram(mProgram);
+    }
+}
+
+
+void ugly::ShaderProgramBuilder::reset() {
+    using namespace std;
+    swap(*this, ShaderProgramBuilder{});
+}
+
+
+ugly::ShaderProgramBuilder &ugly::ShaderProgramBuilder::attachFromMemory(GLenum type, const GLchar *string, GLint length) {
+    auto shader = glCreateShader(type);
+    glShaderSource(shader, 1, &string, length != 0 ? &length : NULL);
+    glCompileShader(shader);
+
+    GLint status;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
+    if(status != GL_TRUE) {
+        char buf[512];
+        glGetShaderInfoLog(shader, 512, NULL, buf);
+        glDeleteShader(shader);
+        std::cerr << "Failed to compile shader:\n\t" << buf << '\n';
+        throw Error{"shader failed to compile"};
+    }
+
+    glAttachShader(mProgram, shader);
+    glDeleteShader(shader);
+    return *this;
+}
+
+
+ugly::ShaderProgramBuilder &ugly::ShaderProgramBuilder::attachFromFile(GLenum type, const char *filename) {
+    auto file = std::ifstream{filename};
+    file.exceptions(std::ios_base::badbit);
+    std::ostringstream ss;
+    ss << file.rdbuf();
+    return attachFromMemory(type, ss.str().c_str());
+}
+
+
+GLuint ugly::ShaderProgramBuilder::link() {
+    glLinkProgram(mProgram);
+    
+    GLint status;
+    glGetProgramiv(mProgram, GL_LINK_STATUS, &status);
+    if(status != GL_TRUE) {
+        char buf[512];
+        glGetProgramInfoLog(mProgram, 512, NULL, buf);
+        std::cerr << "Failed to link program:\n\t" << buf << '\n';
+        throw Error{"program failed to link"};
+    }
+
+    auto result = mProgram;
+    mProgram = 0;
+    reset();
+    return result;
+}