From 1fd8c7691a35ee55eb09451d40e33db790c454e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Thu, 23 May 2013 17:51:01 +0200
Subject: [PATCH] Added AbstractShaderProgram::validate().

---
 src/AbstractShaderProgram.cpp | 19 +++++++++++++++++++
 src/AbstractShaderProgram.h   | 10 ++++++++++
 2 files changed, 29 insertions(+)

diff --git a/src/AbstractShaderProgram.cpp b/src/AbstractShaderProgram.cpp
index 5ecce8aac..df463da19 100644
--- a/src/AbstractShaderProgram.cpp
+++ b/src/AbstractShaderProgram.cpp
@@ -96,6 +96,25 @@ AbstractShaderProgram::~AbstractShaderProgram() {
     if(_id) glDeleteProgram(_id);
 }
 
+std::pair<bool, std::string> AbstractShaderProgram::validate() {
+    glValidateProgram(_id);
+
+    /* Check validation status */
+    GLint success, logLength;
+    glGetProgramiv(_id, GL_VALIDATE_STATUS, &success);
+    glGetProgramiv(_id, GL_INFO_LOG_LENGTH, &logLength);
+
+    /* Error or warning message. The string is returned null-terminated, scrap
+       the \0 at the end afterwards */
+    std::string message(logLength, '\n');
+    if(!message.empty()) {
+        glGetProgramInfoLog(_id, message.size(), nullptr, &message[0]);
+        message.resize(logLength-1);
+    }
+
+    return {success, std::move(message)};
+}
+
 void AbstractShaderProgram::use() {
     /* Use only if the program isn't already in use */
     GLuint& current = Context::current()->state()->shaderProgram->current;
diff --git a/src/AbstractShaderProgram.h b/src/AbstractShaderProgram.h
index a829d1068..a042fdb93 100644
--- a/src/AbstractShaderProgram.h
+++ b/src/AbstractShaderProgram.h
@@ -322,6 +322,16 @@ class MAGNUM_EXPORT AbstractShaderProgram {
         /** @brief OpenGL program ID */
         inline GLuint id() const { return _id; }
 
+        /**
+         * @brief Validate program
+         *
+         * Returns validation status and optional validation message.
+         * @see @fn_gl{ValidateProgram}, @fn_gl{GetProgram} with
+         *      @def_gl{VALIDATE_STATUS}, @def_gl{INFO_LOG_LENGTH},
+         *      @fn_gl{GetProgramInfoLog}
+         */
+        std::pair<bool, std::string> validate();
+
         /**
          * @brief Use shader for rendering
          *