My adaptation of Stanford lecture on OpenGL ES

1. With OpenGL ES
novikov.ruslan@gmail.com

2. IRIS GL
1992

3.  1996 3Dfx createsVoodoo Graphics
 First successful consumer 3D accelerator
 1997 id Software releasesQuake II game
 This game uses Open GL out of the box
 1999 Nvidia releasesGeForce 256
 first consumer-level PC graphics chip with
hardware transform, lighting, and shading

4.  What is OpenGL?
 OpenGL stands for Open Graphics Library. It is a
specification of an API for rendering 3D graphics
 What is NOT OpenGL?
 The OpenGLAPI only deals with rendering graphics.
OpenGL does not provide functions for animations,
timing, image file format processing,GUI etc.
 Is OpenGL Open Source?
 No, OpenGL doesn't have any source code. GL is a
specification

6.  Change Machine State
 glEnable(); glDisable(); glMatrixMode(); glBindFramebufferOES();
glViewport(); glVertexPointer(); glColorPointer(); glTranslatef() ...
 Issue Drawing Commands
 glDrawArrays(); glDrawElements(); ...
 Read Back State, Drawing Results
 glGetBooleanv(); glGetFloatv(); glReadPixels(); ...

7.  Window Coordinates
 Normalized DeviceCoordinates
 Clip and Eye Coordinates
 World Coordinates
 Object Coordinates

13. glMatrixMode(GL_PROJECTION);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glOrthof(left, right, bottom, top, zNear, zFar);
glFrustumf(left, right, bottom, top, zNear, zFar);
glRotatef(degrees, x, y, z);
glTranslatef(x, y, z);
glScalef(x, y, z);
glMultMatrixf(matrix);
glPushMatrix();
glPopMatrix();

14.  OpenGL ES draws triangles, lines, and points
 Object space vertices mapped into window
space
 Rasterize the shapes to get pixels

15.  Each vertex can have a color associated
 RGBA
 Alpha usually means opacity
 Lines and triangles interpolate colors

16.  Vertices are passed to OpenGL ES in arrays
 Drawing modes determine how vertices are
interpreted to produce shapes
 Vertex order matters

17.  Use a triangle strip

19.  Color pixels according to an image in memory
 Almost always 2D
 Vertices are given texture coordinates (u,v)
u
v

20. glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.0f);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texture.name);
GLFloat textureCoordArray[] = {
u1,v1,
u2,v2,
u3,v3, ... };
glTexCoordPointer(2, GL_FLOAT, arrayOffset, textureCoordArray);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glDrawArrays(GL_TRIANGLE_STRIP, arrayOffset, numberOfVertices);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);

21.  https://www.youtube.com/watch?v=_WcMe4
Yj0NM
 http://www.stanford.edu/class/cs193p/cgi-
bin/drupal/node/79
novikov.ruslan@gmail.com