opengl-es-2.0 - w3toppers.com

Modifying camera output using SurfaceTexture and OpenGL

mDirectVideo = new DirectVideo(texture); texture = createTexture(); should be texture = createTexture(); mDirectVideo = new DirectVideo(texture); Shader private final String vertexShaderCode = “attribute vec4 position;” + “attribute vec2 inputTextureCoordinate;” + “varying vec2 textureCoordinate;” + “void main()” + “{“+ “gl_Position = position;”+ “textureCoordinate = inputTextureCoordinate;” + “}”; private final String fragmentShaderCode = “#extension GL_OES_EGL_image_external : require\n”+ … Read more

Appropriate multiplication of matrices for rotation/translation

It looks like the problem is: Matrix.multiplyMV(GLES20Renderer._uBodyCentreMatrix, 0, GLES20Renderer._ModelMatrixBody, 0, GLES20Renderer._uBodyCentre, 0); Matrix.multiplyMV is a method to multiply a 4 element vector by a 4×4 matrix and store the result in a 4 element column vector. In matrix notation: result = lhs x rhs. The resultVector element values are undefined if the resultVector elements overlap … Read more

Drawing a sphere in OpenGL ES

Since you’ve tagged this with OpenGL ES 2.0, let me suggest an alternative approach for creating smooth spheres, and that’s to draw them as raytraced impostors. Rather than calculate the many vertices you’ll need to replicate a smooth sphere, you can take advantage of the fact that a sphere looks pretty much the same from … Read more

OpenGL ES2 Alpha test problems

Here is an overview of a few methods to render with transparency in OpenGL, with advantages and disadvantages for each. Alpha Testing This is a very limited method, but is sufficient for the specific case the poster asked about. The example shown does not really need transparency because everything is either fully opaque or fully … Read more

Faster alternative to glReadPixels in iPhone OpenGL ES 2.0

As of iOS 5.0, there is now a faster way to grab data from OpenGL ES. It isn’t readily apparent, but it turns out that the texture cache support added in iOS 5.0 doesn’t just work for fast upload of camera frames to OpenGL ES, but it can be used in reverse to get quick … Read more