Vertex Attributes, Vertex Arrays, and Buffer Objects - Praise for OpenGL ES 30 Programming Guide - page 134

Example 6-3 Using Constant and Vertex Array Attributes (continued)

"void main() \n"
"{ \n"
" o_fragColor = v_color; \n"
"}" ;

GLuint programObject;

// Create the program object
programObject = esLoadProgram ( vShaderStr, fShaderStr );

if ( programObject == 0 )
return GL_FALSE;

// Store the program object
userData->programObject = programObject;

glClearColor ( 0.0f, 0.0f, 0.0f, 0.0f );
return GL_TRUE;
}

void Draw ( ESContext *esContext )
{
UserData *userData = (UserData*) esContext->userData;
GLfloat color[4] = { 1.0f, 0.0f, 0.0f, 1.0f };
// 3 vertices, with (x, y, z) per-vertex
GLfloat vertexPos[3 * 3] =
{
0.0f, 0.5f, 0.0f, // v0
-0.5f, -0.5f, 0.0f, // v1
0.5f, -0.5f, 0.0f // v2
};
glViewport ( 0, 0, esContext->width, esContext->height );

glClear ( GL_COLOR_BUFFER_BIT );

glUseProgram ( userData->programObject );

glVertexAttrib4fv ( 0, color );
glVertexAttribPointer ( 1, 3, GL_FLOAT, GL_FALSE, 0,
vertexPos );
glEnableVertexAttribArray ( 1 );

glDrawArrays ( GL_TRIANGLES, 0, 3 );

glDisableVertexAttribArray ( 1 );
}