ruby: Remove unused OpenGL functions (ares-emulator#1602)

Removes apparently dead, unused functions in the OpenGL backend.

### Context

Work continues on the new build system. Among its goals are to start
compiling ares with stricter settings, where applicable, to increase
code quality. This includes removing unused functions, to satisfy
`-Wunused-function`.

ruby/video/opengl/utility.hpp

@@ -2,108 +2,3 @@ static auto glrSize(u32 size) -> u32 {
   return size;
 //return bit::round(size);  //return nearest power of two
 }
-
-static auto glrFormat(const string& format) -> GLuint {
-  if(format == "r32i"   ) return GL_R32I;
-  if(format == "r32ui"  ) return GL_R32UI;
-  if(format == "rgba8"  ) return GL_RGBA8;
-  if(format == "rgb10a2") return GL_RGB10_A2;
-  if(format == "rgba12" ) return GL_RGBA12;
-  if(format == "rgba16" ) return GL_RGBA16;
-  if(format == "rgba16f") return GL_RGBA16F;
-  if(format == "rgba32f") return GL_RGBA32F;
-  return GL_RGBA8;
-}
-
-static auto glrFilter(const string& filter) -> GLuint {
-  if(filter == "nearest") return GL_NEAREST;
-  if(filter == "linear" ) return GL_LINEAR;
-  return GL_LINEAR;
-}
-
-static auto glrWrap(const string& wrap)  -> GLuint {
-  if(wrap == "border") return GL_CLAMP_TO_BORDER;
-  if(wrap == "edge"  ) return GL_CLAMP_TO_EDGE;
-  if(wrap == "repeat") return GL_REPEAT;
-  return GL_CLAMP_TO_BORDER;
-}
-
-static auto glrModulo(u32 modulo) -> u32 {
-  if(modulo) return modulo;
-  return 300;  //divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, 25, 30, 50, 60, 100, 150
-}
-
-static auto glrProgram() -> GLuint {
-  GLuint program = 0;
-  glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&program);
-  return program;
-}
-
-static auto glrUniform1i(const string& name, GLint value) -> void {
-  GLint location = glGetUniformLocation(glrProgram(), name);
-  glUniform1i(location, value);
-}
-
-static auto glrUniform4f(const string& name, GLfloat value0, GLfloat value1, GLfloat value2, GLfloat value3) -> void {
-  GLint location = glGetUniformLocation(glrProgram(), name);
-  glUniform4f(location, value0, value1, value2, value3);
-}
-
-static auto glrUniformMatrix4fv(const string& name, GLfloat* values) -> void {
-  GLint location = glGetUniformLocation(glrProgram(), name);
-  glUniformMatrix4fv(location, 1, GL_FALSE, values);
-}
-
-static auto glrParameters(GLuint filter, GLuint wrap) -> void {
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap);
-}
-
-static auto glrCreateShader(GLuint program, GLuint type, const char* source) -> GLuint {
-  GLuint shader = glCreateShader(type);
-  glShaderSource(shader, 1, &source, 0);
-  glCompileShader(shader);
-  GLint result = GL_FALSE;
-  glGetShaderiv(shader, GL_COMPILE_STATUS, &result);
-  if(result == GL_FALSE) {
-    GLint length = 0;
-    glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
-    string text;
-    text.resize(length);
-    glGetShaderInfoLog(shader, length, &length, text.get());
-    text.resize(length);
-    print("[ruby::OpenGL: shader compiler error]\n", text, "\n\n");
-    return 0;
-  }
-  glAttachShader(program, shader);
-  return shader;
-}
-
-static auto glrLinkProgram(GLuint program) -> void {
-  glLinkProgram(program);
-  GLint result = GL_FALSE;
-  glGetProgramiv(program, GL_LINK_STATUS, &result);
-  if(result == GL_FALSE) {
-    GLint length = 0;
-    glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
-    string text;
-    text.resize(length);
-    glGetProgramInfoLog(program, length, &length, text.get());
-    text.resize(length);
-    print("[ruby::OpenGL: shader linker error]\n", text, "\n\n");
-  }
-  glValidateProgram(program);
-  result = GL_FALSE;
-  glGetProgramiv(program, GL_VALIDATE_STATUS, &result);
-  if(result == GL_FALSE) {
-    GLint length = 0;
-    glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
-    string text;
-    text.resize(length);
-    glGetProgramInfoLog(program, length, &length, text.get());
-    text.resize(length);
-    print("[ruby::OpenGL: shader validation error]\n", text, "\n\n");
-  }
-}