Added gyp file for examples. Removed unnecessary functions. Added header file...

third_party/gles_book_examples/Chapter_8/Simple_VertexShader/Simple_VertexShader.c

 //
 // 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
 //
 
 // Simple_VertexShader.c
 //
 //    This is a simple example that draws a rotating cube in perspective
 //    using a vertex shader to transform the object
 //
+
+#include "Simple_VertexShader.h"
 #include <stdlib.h>
-#include "esUtil.h"
-
-typedef struct
-{
-   // Handle to a program object
-   GLuint programObject;
-
-   // Attribute locations
-   GLint  positionLoc;
-
-   // Uniform locations
-   GLint  mvpLoc;
-   
-   // Vertex daata
-   GLfloat  *vertices;
-   GLuint   *indices;
-   int       numIndices;
-
-   // Rotation angle
-   GLfloat   angle;
-
-   // MVP matrix
-   ESMatrix  mvpMatrix;
-} UserData;
 
 ///
 // Initialize the shader and program object
 //
-int Init ( ESContext *esContext )
+int svsInit ( ESContext *esContext )
 {
-   UserData *userData = esContext->userData;
+   SVSUserData *userData = esContext->userData;
    GLbyte vShaderStr[] =  
       "uniform mat4 u_mvpMatrix;                   \n"
       "attribute vec4 a_position;                  \n"
       "void main()                                 \n"
       "{                                           \n"
       "   gl_Position = u_mvpMatrix * a_position;  \n"
       "}                                           \n";
    
+   // TODO(alokp): Shaders containing "precision" do not compile.
    GLbyte fShaderStr[] =  
-      "precision mediump float;                            \n"
+      "//precision mediump float;                            \n"
       "void main()                                         \n"
       "{                                                   \n"
       "  gl_FragColor = vec4( 1.0, 0.0, 0.0, 1.0 );        \n"
       "}                                                   \n";
 
    // Load the shaders and get a linked program object
    userData->programObject = esLoadProgram ( vShaderStr, fShaderStr );
 
    // Get the attribute locations
    userData->positionLoc = glGetAttribLocation ( userData->programObject, "a_position" );
 
    // Get the uniform locations
    userData->mvpLoc = glGetUniformLocation( userData->programObject, "u_mvpMatrix" );
    
    // Generate the vertex data
    userData->numIndices = esGenCube( 1.0, &userData->vertices,
                                      NULL, NULL, &userData->indices );
    
    // Starting rotation angle for the cube
    userData->angle = 45.0f;
 
    glClearColor ( 0.0f, 0.0f, 0.0f, 0.0f );
    return TRUE;
 }
 
-
 ///
 // Update MVP matrix based on time
 //
-void Update ( ESContext *esContext, float deltaTime )
+void svsUpdate ( ESContext *esContext, float deltaTime )
 {
-   UserData *userData = (UserData*) esContext->userData;
+   SVSUserData *userData = (SVSUserData*) esContext->userData;
    ESMatrix perspective;
    ESMatrix modelview;
    float    aspect;
    
    // Compute a rotation angle based on time to rotate the cube
    userData->angle += ( deltaTime * 40.0f );
    if( userData->angle >= 360.0f )
       userData->angle -= 360.0f;
 
    // Compute the window aspect ratio
@@ skipping 13 matching lines @@
    esRotate( &modelview, userData->angle, 1.0, 0.0, 1.0 );
    
    // Compute the final MVP by multiplying the 
    // modevleiw and perspective matrices together
    esMatrixMultiply( &userData->mvpMatrix, &modelview, &perspective );
 }
 
 ///
 // Draw a triangle using the shader pair created in Init()
 //
-void Draw ( ESContext *esContext )
+void svsDraw ( ESContext *esContext )
 {
-   UserData *userData = esContext->userData;
+   SVSUserData *userData = esContext->userData;
    
    // Set the viewport
    glViewport ( 0, 0, esContext->width, esContext->height );
    
    
    // Clear the color buffer
    glClear ( GL_COLOR_BUFFER_BIT );
 
    // Use the program object
    glUseProgram ( userData->programObject );
 
    // Load the vertex position
    glVertexAttribPointer ( userData->positionLoc, 3, GL_FLOAT, 
                            GL_FALSE, 3 * sizeof(GLfloat), userData->vertices );
    
    glEnableVertexAttribArray ( userData->positionLoc );
    
    
    // Load the MVP matrix
    glUniformMatrix4fv( userData->mvpLoc, 1, GL_FALSE, (GLfloat*) &userData->mvpMatrix.m[0][0] );
    
    // Draw the cube
    glDrawElements ( GL_TRIANGLES, userData->numIndices, GL_UNSIGNED_INT, userData->indices );
 
-   eglSwapBuffers ( esContext->eglDisplay, esContext->eglSurface );
+   // TODO(alokp): glFlush should not be necessary with SwapBuffers.
+   glFlush();
 }
 
 ///
 // Cleanup
 //
-void ShutDown ( ESContext *esContext )
+void svsShutDown ( ESContext *esContext )
 {
-   UserData *userData = esContext->userData;
+   SVSUserData *userData = esContext->userData;
 
    if ( userData->vertices != NULL )
    {
       free ( userData->vertices );
    }
 
    if ( userData->indices != NULL )
    {
       free ( userData->indices );
    }
 
    // Delete program object
    glDeleteProgram ( userData->programObject );
 }
-
-
-int main ( int argc, char *argv[] )
-{
-   ESContext esContext;
-   UserData  userData;
-
-   esInitContext ( &esContext );
-   esContext.userData = &userData;
-
-   esCreateWindow ( &esContext, "Simple Texture 2D", 320, 240, ES_WINDOW_RGB );
-   
-   if ( !Init ( &esContext ) )
-      return 0;
-
-   esRegisterDrawFunc ( &esContext, Draw );
-   esRegisterUpdateFunc ( &esContext, Update );
-   
-   esMainLoop ( &esContext );
-
-   ShutDown ( &esContext );
-}