GLES

• glEGLImageTargetTexture2DOES
  • Desc
    • an OpenGL ES extension function
    • allow an EGLImage to be used as the source of data for an OpenGL ES 2D texture
    • allow app to use image data from sources outside the OpenGL ES context (video streams, OpenCL…)
  • Spec:

glBindBuffer & glBindBufferBase

• glBindBuffer is used to bind a buffer to a specific target so that all operations which modify that target are mapped to that buffer afterwards
• glBindBufferBase is used for a totally different purpose.
  • it’s used to bind a buffer to a specific binding point in an indexed array (when data is not supposed to be directly modified but rather used)
  • 
  • glBindBufferBase is creating the arrows on the right
  • get block index: glGetUniformBLockIndex
  • link to the binding point: glUniformBlockBinding
• indexed binding points

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GLuint bufferIDs[2];
glGenBuffers(2, bufferIDs);

// Bind buffer object 1 to binding points 0
glBindBufferBase(GL_UNIFORM_BUFFER, 0, bufferIDs[0]);

// Bind buffer object 2 to binding points 1
glBindBufferBase(GL_UNIFORM_BUFFER, 1, bufferIDs[1]);

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layout(std140, binding = 0) uniform MyBlock1 {
    // Uniform variables for block 1
};

layout(std140, binding = 1) uniform MyBlock2 {
    // Uniform variables for block 2
};

• binding = 0 <–> bufferIDs[0]
• binding = 1 <–> bufferIDs[1]
• we can change the binding points to switch between different sets of uniform data during rending, without the need to recompiling or relinking the shader program