Presentation of the CeedMath & CeedGL open source libraries for easier computer graphics programming on Mac & iOS

1. CeedMath & CeedGL
Let’s talk 3D...
web:
www.creaceed.com
twitter:
@rsebbe
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2. Overview
• CeedMath & CeedGL are libraries for easier
computer graphics development on Mac & iOS
• BSD license
• Available on Github
• https://github.com/rsebbe/CeedMath
• https://github.com/rsebbe/CeedGL

3. Overview
App
Ceed3DGL Ceed3DRenderMan ...
CeedGL
Ceed3D
GL CeedMath Foundation

4. CeedMath

5. Why?
• CG math libs are generally written in C++
• C++ is cumbersome when developing in
Objective-C
• Need of a pure C library
• Need for both float & double data type

6. Definition
• Written in pure C
• Macro-based templates, float & double
• Simple types (float*)
• Chain-able
• C++ interoperable (polymorphic)
• In C, use _f or _d suffixes
• In C++, automatic based on param type

7. Types
• vector (2D, 3D, 4D)
• normal (3D) / plane (4D)
• matrix (2D, 4D)
• quaternion (4D)
• ray
• box
• frustum
• triangle

8. What?
• vector: add, subtract, dot/vect product, norm,
rotate, project, find angles, lerp...
• matrix: add, subtract, multiply, transform,
solve, invert...
• quaternion: standard operations...
• ray: intersections w/ plane/triangle/box...
• box: union / intersection...
• frustum: perspective transform...
• triangle: normal computation

9. Xcode Project
• Universal: Mac & iOS libs
• Headers note
• lib: PUBLIC_HEADERS_FOLDER_PATH = /usr/local/include/CeedMath
• app: HEADER_SEARCH_PATHS = "$(DSTROOT)/usr/local/include" "$
(CONFIGURATION_BUILD_DIR)/usr/local/include"
• #include <CeedMath/C3Math.h>

10. Demo
• Demo #1: template mechanics
• Demo #2: real world example (rounded rect)
C3MeshGeometry+Primitives.mm
• Demo #3: C++ templates for mouse picking
C3StreamPrimitive+Picking.mm

11. Demo

12. Demo’s

13. CeedGL

14. Why?
• OpenGL is a C API, most GL objects are int’s
• Error prone, all function take int’s
• Complex APIs, many functions
• Not practical within Objective-C
• Intimidating, hard to start
• Higher level abstractions exist (scene
graphs), but what if you only need standard
OpenGL?

15. Old vs. Modern OpenGL
OpenGL 1.x, 2.x OpenGL ES 1.x
define camera position, define object position, choose a
predefined illumination model, place the lights, draw some
triangles, change position, draw some other...
OpenGL >= 3.1 OpenGL ES 2.x + WebGL
set vertices, indices, shading program & params, then draw

16. OpenGL
• Modern OpenGL programming is hard.
Especially the first time...
• It’s a functional C API
• Most “objects” are represented by handles (int)
• Modern GL has removed many concepts
• Light, shading, transforms
• For the good, the old pipeline was limiting, and
a hurdle for card makers
• It is now more in sync w/ hardware capabilities

17. CeedGL
• CeedGL does not define new concepts
• But it helps in setting up and managing your
OpenGL objects
• Thin Objective-C Wrapper

18. CeedGL
GLObject
GLFramebuffer GLRenderbuffer
GLBuffer GLTexture GLShader GLProgram
GLValue
GLDrawCommand

19. Draw (1/2)
• Vertex Shader
• 1 execution per vertex
• inputs: uniform, attribute
• output: varying
• Fragment Shader
• 1 execution per output
pixel
• input: uniform, varying
• output: fragment color

20. Draw (2/2)
GLDrawCommand GLFramebuffer
GLProgram u GLValue GLRenderbuffer
v GLShader a GLValue GLTexture
f GLShader a GLBuffer
i GLBuffer
t GLTexture

21. Demo’s

22. GLKit?
• GLKit’s Math
• NEON optimized
• Currently iOS5 only, definitely Apple only
• Has an overlap with CeedMath
• GLKit’s GL
• Forces a GL coding style
• Provides easier starting point
• Mostly complementary to CeedGL
• Permissive, forkable open source make
sense in such projects

23. Happy 3D coding !
web:
www.creaceed.com
twitter:
@rsebbe
cocoaheads.be