1 files changed, 155 insertions, 0 deletions
diff --git a/src/es/esShader.c b/src/es/esShader.c
new file mode 100644
index 0000000..4ea2cbc
--- /dev/null
+++ b/src/es/esShader.c
@@ -0,0 +1,155 @@
+//
+// Book:      OpenGL(R) ES 2.0 Programming Guide
+// Authors:   Aaftab Munshi, Dan Ginsburg, Dave Shreiner
+// ISBN-10:   0321502795
+// ISBN-13:   9780321502797
+// Publisher: Addison-Wesley Professional
+// URLs:      http://safari.informit.com/9780321563835
+//            http://www.opengles-book.com
+//
+
+// ESShader.c
+//
+//    Utility functions for loading shaders and creating program objects.
+//
+
+///
+//  Includes
+//
+#include "esUtil.h"
+#include <stdlib.h>
+
+//////////////////////////////////////////////////////////////////
+//
+//  Private Functions
+//
+//
+
+
+
+//////////////////////////////////////////////////////////////////
+//
+//  Public Functions
+//
+//
+
+//
+///
+/// \brief Load a shader, check for compile errors, print error messages to output log
+/// \param type Type of shader (GL_VERTEX_SHADER or GL_FRAGMENT_SHADER)
+/// \param shaderSrc Shader source string
+/// \return A new shader object on success, 0 on failure
+//
+GLuint ESUTIL_API esLoadShader ( GLenum type, const char *shaderSrc )
+{
+   GLuint shader;
+   GLint compiled;
+   
+   // Create the shader object
+   shader = glCreateShader ( type );
+
+   if ( shader == 0 )
+   	return 0;
+
+   // Load the shader source
+   glShaderSource ( shader, 1, &shaderSrc, NULL );
+   
+   // Compile the shader
+   glCompileShader ( shader );
+
+   // Check the compile status
+   glGetShaderiv ( shader, GL_COMPILE_STATUS, &compiled );
+
+   if ( !compiled ) 
+   {
+      GLint infoLen = 0;
+
+      glGetShaderiv ( shader, GL_INFO_LOG_LENGTH, &infoLen );
+      
+      if ( infoLen > 1 )
+      {
+         char* infoLog = malloc (sizeof(char) * infoLen );
+
+         glGetShaderInfoLog ( shader, infoLen, NULL, infoLog );
+         esLogMessage ( "Error compiling shader:\n%s\n", infoLog );            
+         
+         free ( infoLog );
+      }
+
+      glDeleteShader ( shader );
+      return 0;
+   }
+
+   return shader;
+
+}
+
+
+//
+///
+/// \brief Load a vertex and fragment shader, create a program object, link program.
+//         Errors output to log.
+/// \param vertShaderSrc Vertex shader source code
+/// \param fragShaderSrc Fragment shader source code
+/// \return A new program object linked with the vertex/fragment shader pair, 0 on failure
+//
+GLuint ESUTIL_API esLoadProgram ( const char *vertShaderSrc, const char *fragShaderSrc )
+{
+   GLuint vertexShader;
+   GLuint fragmentShader;
+   GLuint programObject;
+   GLint linked;
+
+   // Load the vertex/fragment shaders
+   vertexShader = esLoadShader ( GL_VERTEX_SHADER, vertShaderSrc );
+   if ( vertexShader == 0 )
+      return 0;
+
+   fragmentShader = esLoadShader ( GL_FRAGMENT_SHADER, fragShaderSrc );
+   if ( fragmentShader == 0 )
+   {
+      glDeleteShader( vertexShader );
+      return 0;
+   }
+
+   // Create the program object
+   programObject = glCreateProgram ( );
+   
+   if ( programObject == 0 )
+      return 0;
+
+   glAttachShader ( programObject, vertexShader );
+   glAttachShader ( programObject, fragmentShader );
+
+   // Link the program
+   glLinkProgram ( programObject );
+
+   // Check the link status
+   glGetProgramiv ( programObject, GL_LINK_STATUS, &linked );
+
+   if ( !linked ) 
+   {
+      GLint infoLen = 0;
+
+      glGetProgramiv ( programObject, GL_INFO_LOG_LENGTH, &infoLen );
+      
+      if ( infoLen > 1 )
+      {
+         char* infoLog = malloc (sizeof(char) * infoLen );
+
+         glGetProgramInfoLog ( programObject, infoLen, NULL, infoLog );
+         esLogMessage ( "Error linking program:\n%s\n", infoLog );            
+         
+         free ( infoLog );
+      }
+
+      glDeleteProgram ( programObject );
+      return 0;
+   }
+
+   // Free up no longer needed shader resources
+   glDeleteShader ( vertexShader );
+   glDeleteShader ( fragmentShader );
+
+   return programObject;
+}
+\ No newline at end of file