CeedMath & CeedGLLet’s talk 3D...

web: www.creaceed.comtwitter : @rsebbe

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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

Overview

CeedMath Foundation

Ceed3D

Ceed3DGL Ceed3DRenderMan ...

App

GL

Cee

dGL

CeedMath

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

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

Types

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

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

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>

Demo

• Demo #1: template mechanics

• Demo #2: real world example (rounded rect)

• Demo #3: C++ templates for mouse pickingC3StreamPrimitive+Picking.mm

C3MeshGeometry+Primitives.mm

Demo

Demo’s

CeedGL

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?

Old vs. Modern OpenGL

define camera position, define object position, choose a predefined illumination model, place the lights, draw some

triangles, change position, draw some other...

set vertices, indices, shading program & params, then draw

OpenGL 1.x, 2.x OpenGL ES 1.x

OpenGL >= 3.1 OpenGL ES 2.x + WebGL

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

CeedGL• CeedGL does not define new concepts• But it helps in setting up and managing your

OpenGL objects• Thin Objective-C Wrapper

CeedGLGLObject

GLBuffer GLTexture

GLFramebuffer GLRenderbuffer

GLShader GLProgram

GLDrawCommand

GLValue

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

Draw (2/2)

GLBuffer

GLTexture

GLFramebuffer

GLRenderbuffer

GLShader

GLProgram

GLDrawCommand

GLValue

GLShader

vf

GLBuffer

GLValue

GLTexture

uaait

Demo’s

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

Happy 3D coding !

web: www.creaceed.comtwitter : @rsebbe

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