I'm working on a mobile application for Symbian 5th edition using OpenGLES.
This application is a pretty standard 2D app, and I make no use of the DepthBuffer.
I need to grab a snapshot of the display and then draw the very same snapshot back to the backbuffer.
I'm using glReadPixels((GLint)0, (GLint)0,
(GLint)nWidth-1, (GLint)nHeight-1,
GL_RGB, GL_UNSIGNED_BYTE, m_pPixelData)
in order to get the pixel data I need, but I'm rather new to OpenGLES and I don't know how to draw the data back to the backbuffer. (in OpenGL its easy using DrawPixels..)
I've read that I should generate a texture from the data, so I did. But now I'm not sure how to draw this texture.
Do I need to draw it as a texture of a Rectangular element ? if so than how am I suppose to define this rect ? ( the coordinates just doesn't make sense to me..)
The display size is 480x640 and here is the code I want to use in order to draw the rect:
glEnable(GL_TEXTURE_2D);
//displayTex is my texture built out of the pixel data
glBindTexture(GL_TEXTURE_2D, m_pESSharedData->displayTex);
//Bottom
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-2.5f, -2.5f, 2.5f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(2.5f, -2.5f, 2.5f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(2.5f, -2.5f, -2.5f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-2.5f, -2.5f, -2.5f);
glEnd();
Note that above code is something I've picked up along the way, and I think this is the outline of what I'm suppose to do. feel free to take me off this track. :)
I thank you for your time.