struct Vertex
{
GLfloat x, y;
GLfloat r, g, b, a;
GLfloat tu, tv;
};
#define VERTEX_ARRAY 0
#define VERTEXCOLOR_ARRAY 1
#define TEXCOORD_ARRAY 2
I use it for draw 2D primitives.
test platform - Samsung Galaxy Tab
today I lunch app on the Sumsung Galaxy S II
I am in shock - there x/y is texture coord and tu/tv is world coordinats. They are reversed!!!
this is my shader
attribute vec4 vPosition;
attribute mediump vec4 vColor;
attribute mediump vec2 uv;
varying mediump vec4 vVertexColor;
varying mediump vec2 myTexCoord;
void main()
{
gl_Position = vPosition;
vVertexColor = vColor;
myTexCoord = uv;
}
precision mediump float;
uniform sampler2D sampler2d;
varying mediump vec4 vVertexColor;
varying mediump vec2 myTexCoord;
void main()
{
gl_FragColor = texture2D( sampler2d, myTexCoord) * vVertexColor ;
}
this is render function for draw all primitives
glBindBuffer( GL_ARRAY_BUFFER, vertexBuffer );// Bind the VBO. glBufferSubData( GL_ARRAY_BUFFER, 0, m_CurrentVertexIndex * g_ui32VertexStride, vertices ); glEnableVertexAttribArray( VERTEX_ARRAY ); glVertexAttribPointer( VERTEX_ARRAY, 2, GL_FLOAT, GL_FALSE, g_ui32VertexStride, 0 ); glEnableVertexAttribArray( VERTEXCOLOR_ARRAY ); glVertexAttribPointer( VERTEXCOLOR_ARRAY, 4, GL_FLOAT, GL_FALSE, g_ui32VertexStride, (void*) (2 * sizeof(GLfloat) ) ); glEnableVertexAttribArray( TEXCOORD_ARRAY ); glVertexAttribPointer( TEXCOORD_ARRAY, 2, GL_FLOAT, GL_FALSE, g_ui32VertexStride, (void*) (6 * sizeof(GLfloat) ) ); glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, indexBuffer ); glDrawElements( GL_TRIANGLES, 3 * m_RenderTriangleCount, GL_UNSIGNED_SHORT, (void*)0);
How to fix it? How to setup for GL that first is world coord, next is color and next is texture coord?