GLApp Class Reference

Simple app runner with a GL context, stock shaders, and draw helpers. More...

#include <GLApp.h>

Collaboration diagram for GLApp:

Public Member Functions
	GLApp (uint32_t w=640, uint32_t h=480, uint32_t s=4, const std::string &title="My OpenGL App", bool fpsCounter=true, bool sync=true)
	Construct the environment and boot the stock shaders/buffers.
virtual	~GLApp ()
	Virtual destructor.
void	run ()
	Create the context/window and enter the render loop.
void	setAnimation (bool animationActive)
	Enable/disable the animation step inside the main loop.
bool	getAnimation () const
	Query whether animation is currently active.
void	resetAnimation ()
	Reset the animation timer and invoke animate(0).
float	getAspect () const
	Current window aspect ratio (width/height).
void	setImageFilter (GLint magFilter, GLint minFilter)
	Update filtering for images drawn by drawImage().
virtual void	init ()
	One‑time initialization hook (resources, buffers, etc.).
virtual void	draw ()
	Per‑frame draw hook.
virtual void	animate (double animationTime)
	Per‑frame animation/update hook; parameter is seconds since start.
virtual void	resize (int width, int height)
	Resize notification; override to update projection, etc.
virtual void	keyboard (int key, int scancode, int action, int mods)
	Keyboard event; parameters mirror backend callbacks.
virtual void	keyboardChar (unsigned int key)
	Unicode character input.
virtual void	mouseMove (double xPosition, double yPosition)
	Mouse move event (window coordinates).
virtual void	mouseButton (int button, int state, int mods, double xPosition, double yPosition)
	Mouse button event with cursor position.
virtual void	mouseWheel (double x_offset, double y_offset, double xPosition, double yPosition)
	Mouse wheel/trackpad scroll event with cursor position.
Rect / textured quad
void	drawRect (const Vec4 &color, const Vec2 &bl, const Vec2 &tr)
	Draw a solid‑color rectangle given 2D corners.
void	drawRect (const Vec4 &color, const Vec3 &bl=Vec3{-1.0f,-1.0f, 0.0f}, const Vec3 &br=Vec3{1.0f,-1.0f, 0.0f}, const Vec3 &tl=Vec3{-1.0f, 1.0f, 0.0f}, const Vec3 &tr=Vec3{1.0f, 1.0f, 0.0f})
	Draw a solid‑color rectangle given 3D corners (defaults to NDC quad).
void	drawImage (const GLTexture2D &image, const Vec2 &bl, const Vec2 &tr)
	Draw a textured quad from a texture handle using 2D corners.
void	drawImage (const Image &image, const Vec2 &bl, const Vec2 &tr)
	Draw a textured quad from an Image using 2D corners.
void	drawImage (const GLTexture2D &image, const Vec3 &bl=Vec3{-1.0f,-1.0f, 0.0f}, const Vec3 &br=Vec3{1.0f,-1.0f, 0.0f}, const Vec3 &tl=Vec3{-1.0f, 1.0f, 0.0f}, const Vec3 &tr=Vec3{1.0f, 1.0f, 0.0f})
	Draw a textured quad from a texture handle using 3D corners.
void	drawImage (const Image &image, const Vec3 &bl=Vec3{-1.0f,-1.0f, 0.0f}, const Vec3 &br=Vec3{1.0f,-1.0f, 0.0f}, const Vec3 &tl=Vec3{-1.0f, 1.0f, 0.0f}, const Vec3 &tr=Vec3{1.0f, 1.0f, 0.0f})
	Draw a textured quad from an Image using 3D corners.
Primitives
void	drawPoints (const std::vector< float > &data, float pointSize=1.0f, bool useTex=false)
	Draw an array of colored points.
void	drawLines (const std::vector< float > &data, LineDrawType t, float lineThickness=1.0f)
	Draw colored lines using the given topology.
void	drawTriangles (const std::vector< float > &data, TrisDrawType t, bool wireframe, bool lighting)
	Upload triangle data and draw immediately (or as wireframe edges).
void	redrawTriangles (bool wireframe)
	Re‑issue the last triangle draw using cached settings.
Transforms
Mat4	computeImageTransform (const Vec2ui &imageSize) const
	Compute a uniform image scale so the longer side fits the window.
Mat4	computeImageTransformFixedHeight (const Vec2ui &imageSize, float height=1.0f, const Vec3 &center=Vec3{0.0f, 0.0f, 0.0f}) const
	Compute a transform that fits an image to a given height.
Mat4	computeImageTransformFixedWidth (const Vec2ui &imageSize, float width=1.0f, const Vec3 &center=Vec3{0.0f, 0.0f, 0.0f}) const
	Compute a transform that fits an image to a given width.
View/projection
void	setDrawProjection (const Mat4 &mat)
	Set the projection matrix used by the stock shaders.
void	setDrawTransform (const Mat4 &mat)
	Set the model‑view matrix used by the stock shaders.
Mat4	getDrawProjection () const
	Current projection matrix.
Mat4	getDrawTransform () const
	Current model‑view matrix.
Point sprite textures
void	resetPointTexture (uint32_t resolution=64)
	Create a default circular mask texture of given resolution.
void	setPointTexture (const std::vector< uint8_t > &shape, uint32_t x, uint32_t y, uint8_t components)
	Set the point sprite from raw bytes.
void	setPointTexture (const Image &shape)
	Set the point sprite from an Image.
void	setPointHighlightTexture (const Image &shape)
	Set an optional highlight overlay sprite from an Image.
void	resetPointHighlightTexture ()
	Clear the highlight overlay sprite.

Protected Member Functions
void	shaderUpdate ()
	Update stock shader uniforms (MVP/MV/MVit) to current transforms.
void	closeWindow ()
	Request closing the window.

Protected Attributes
GLEnv	glEnv
	Window/context + platform utilities.
Mat4	p
	Projection matrix used by stock shaders.
Mat4	mv
	Model‑view matrix used by stock shaders.
Mat4	mvi
	Inverse of mv (for lighting helpers).
GLProgram	simpleProg
	Solid color shader (pos+color).
GLProgram	simplePointProg
	Point shader (pos+color), desktop uses glPointSize.
GLProgram	simpleSpriteProg
	Point sprite shader (pos+color+texture).
GLProgram	simpleHLSpriteProg
	Point sprite + highlight overlay.
GLProgram	simpleTexProg
	Textured quad shader (pos+uv).
GLProgram	simpleLightProg
	Lit shader (pos+color+normal).
GLArray	simpleArray
	VAO used by helpers.
GLBuffer	simpleVb
	VBO used by helpers.
GLTexture2D	raster
	Temporary texture for drawImage(Image).
GLTexture2D	pointSprite
	Point‑sprite base texture.
GLTexture2D	pointSpriteHighlight
	Optional highlight overlay sprite.
double	resumeTime
	Timestamp used to keep animation time continuous on resume.

Detailed Description

Simple app runner with a GL context, stock shaders, and draw helpers.

Typical usage:

 struct MyApp : GLApp {
   void init() override { /* load data */ }
  void draw() override { /* issue draws */ }
  void animate(double t) override { /* update state */ }
};
int main(){ MyApp().run(); }

Constructor & Destructor Documentation

GLApp()

GLApp::GLApp	(	uint32_t	w = 640,
		uint32_t	h = 480,
		uint32_t	s = 4,
		const std::string &	title = "My OpenGL App",
		bool	fpsCounter = true,
		bool	sync = true )

Construct the environment and boot the stock shaders/buffers.

Parameters

w	Window width in pixels.
h	Window height in pixels.
s	Multisample count (GLFW window hint).
title	Window/page title.
fpsCounter	If true, show an FPS counter in the title.
sync	If true, enable vsync.

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~GLApp()

GLApp::~GLApp ( )

virtual

Virtual destructor.

Member Function Documentation

animate()

virtual void GLApp::animate ( double animationTime )

inlinevirtual

Per‑frame animation/update hook; parameter is seconds since start.

closeWindow()

void GLApp::closeWindow ( )

inlineprotected

Request closing the window.

computeImageTransform()

Mat4 GLApp::computeImageTransform

(

const Vec2ui &

imageSize

)

const

Compute a uniform image scale so the longer side fits the window.

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computeImageTransformFixedHeight()

Mat4 GLApp::computeImageTransformFixedHeight	(	const Vec2ui &	imageSize,
		float	height = 1.0f,
		const Vec3 &	center = Vec3{0.0f,0.0f,0.0f} ) const

Compute a transform that fits an image to a given height.

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computeImageTransformFixedWidth()

Mat4 GLApp::computeImageTransformFixedWidth	(	const Vec2ui &	imageSize,
		float	width = 1.0f,
		const Vec3 &	center = Vec3{0.0f,0.0f,0.0f} ) const

Compute a transform that fits an image to a given width.

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draw()

virtual void GLApp::draw ( )

inlinevirtual

Per‑frame draw hook.

drawImage() [1/4]

void GLApp::drawImage	(	const GLTexture2D &	image,
		const Vec2 &	bl,
		const Vec2 &	tr )

Draw a textured quad from a texture handle using 2D corners.

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drawImage() [2/4]

void GLApp::drawImage	(	const GLTexture2D &	image,
		const Vec3 &	bl = Vec3{-1.0f,-1.0f,0.0f},
		const Vec3 &	br = Vec3{1.0f,-1.0f,0.0f},
		const Vec3 &	tl = Vec3{-1.0f,1.0f,0.0f},
		const Vec3 &	tr = Vec3{1.0f,1.0f,0.0f} )

Draw a textured quad from a texture handle using 3D corners.

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drawImage() [3/4]

void GLApp::drawImage	(	const Image &	image,
		const Vec2 &	bl,
		const Vec2 &	tr )

Draw a textured quad from an Image using 2D corners.

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drawImage() [4/4]

void GLApp::drawImage	(	const Image &	image,
		const Vec3 &	bl = Vec3{-1.0f,-1.0f,0.0f},
		const Vec3 &	br = Vec3{1.0f,-1.0f,0.0f},
		const Vec3 &	tl = Vec3{-1.0f,1.0f,0.0f},
		const Vec3 &	tr = Vec3{1.0f,1.0f,0.0f} )

Draw a textured quad from an Image using 3D corners.

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drawLines()

void GLApp::drawLines	(	const std::vector< float > &	data,
		LineDrawType	t,
		float	lineThickness = 1.0f )

Draw colored lines using the given topology.

Parameters

data	Interleaved vertices (x,y,z,r,g,b,a) → 7 floats.
t	Topology: LIST/STRIP/LOOP.
lineThickness	If >1, thick lines are triangulated in screen space.

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drawPoints()

void GLApp::drawPoints	(	const std::vector< float > &	data,
		float	pointSize = 1.0f,
		bool	useTex = false )

Draw an array of colored points.

Parameters

data	Interleaved floats per vertex (x,y,z,r,g,b,a) → 7 floats.
pointSize	Pixel size (ignored on desktop when using simplePointProg).
useTex	If true, draw as point sprites using the configured textures.

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drawRect() [1/2]

void GLApp::drawRect	(	const Vec4 &	color,
		const Vec2 &	bl,
		const Vec2 &	tr )

Draw a solid‑color rectangle given 2D corners.

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drawRect() [2/2]

void GLApp::drawRect	(	const Vec4 &	color,
		const Vec3 &	bl = Vec3{-1.0f,-1.0f,0.0f},
		const Vec3 &	br = Vec3{1.0f,-1.0f,0.0f},
		const Vec3 &	tl = Vec3{-1.0f,1.0f,0.0f},
		const Vec3 &	tr = Vec3{1.0f,1.0f,0.0f} )

Draw a solid‑color rectangle given 3D corners (defaults to NDC quad).

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drawTriangles()

void GLApp::drawTriangles	(	const std::vector< float > &	data,
		TrisDrawType	t,
		bool	wireframe,
		bool	lighting )

Upload triangle data and draw immediately (or as wireframe edges).

Parameters

data	Interleaved floats per vertex; 7 floats for color only (x,y,z,r,g,b,a) or 10 floats when lighting is enabled (x,y,z,r,g,b,a,nx,ny,nz).
t	Topology: LIST/STRIP/FAN.
wireframe	If true, edges are derived and drawn as lines.
lighting	If true, expect normals and use the lighting shader.

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getAnimation()

bool GLApp::getAnimation

(

)

const

Query whether animation is currently active.

getAspect()

float GLApp::getAspect

(

)

const

Current window aspect ratio (width/height).

getDrawProjection()

Mat4 GLApp::getDrawProjection

(

)

const

Current projection matrix.

getDrawTransform()

Mat4 GLApp::getDrawTransform

(

)

const

Current model‑view matrix.

init()

virtual void GLApp::init ( )

inlinevirtual

One‑time initialization hook (resources, buffers, etc.).

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keyboard()

virtual void GLApp::keyboard ( int key, int scancode, int action, int mods )

inlinevirtual

Keyboard event; parameters mirror backend callbacks.

keyboardChar()

virtual void GLApp::keyboardChar ( unsigned int key )

inlinevirtual

Unicode character input.

mouseButton()

virtual void GLApp::mouseButton ( int button, int state, int mods, double xPosition, double yPosition )

inlinevirtual

Mouse button event with cursor position.

mouseMove()

virtual void GLApp::mouseMove ( double xPosition, double yPosition )

inlinevirtual

Mouse move event (window coordinates).

mouseWheel()

virtual void GLApp::mouseWheel ( double x_offset, double y_offset, double xPosition, double yPosition )

inlinevirtual

Mouse wheel/trackpad scroll event with cursor position.

redrawTriangles()

void GLApp::redrawTriangles

(

bool

wireframe

)

Re‑issue the last triangle draw using cached settings.

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resetAnimation()

void GLApp::resetAnimation

(

)

Reset the animation timer and invoke animate(0).

resetPointHighlightTexture()

void GLApp::resetPointHighlightTexture

(

)

Clear the highlight overlay sprite.

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resetPointTexture()

void GLApp::resetPointTexture

(

uint32_t

resolution = 64

)

Create a default circular mask texture of given resolution.

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resize()

void GLApp::resize ( int width, int height )

virtual

Resize notification; override to update projection, etc.

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run()

void GLApp::run

(

)

Create the context/window and enter the render loop.

Calls init(), then resize() with the framebuffer size, and finally enters the platform‑specific main loop that repeatedly calls animate() and draw() until the window closes.

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setAnimation()

void GLApp::setAnimation

(

bool

animationActive

)

Enable/disable the animation step inside the main loop.

Parameters

animationActive

If true, animate() is called each frame.

Pausing stores a timestamp so resuming keeps animation time continuous.

setDrawProjection()

void GLApp::setDrawProjection

(

const Mat4 &

mat

)

Set the projection matrix used by the stock shaders.

setDrawTransform()

void GLApp::setDrawTransform

(

const Mat4 &

mat

)

Set the model‑view matrix used by the stock shaders.

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setImageFilter()

void GLApp::setImageFilter	(	GLint	magFilter,
		GLint	minFilter )

Update filtering for images drawn by drawImage().

Parameters

magFilter	GL magnification filter.
minFilter	GL minification filter.

setPointHighlightTexture()

void GLApp::setPointHighlightTexture

(

const Image &

shape

)

Set an optional highlight overlay sprite from an Image.

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setPointTexture() [1/2]

void GLApp::setPointTexture

(

const Image &

shape

)

Set the point sprite from an Image.

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setPointTexture() [2/2]

void GLApp::setPointTexture	(	const std::vector< uint8_t > &	shape,
		uint32_t	x,
		uint32_t	y,
		uint8_t	components )

Set the point sprite from raw bytes.

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shaderUpdate()

void GLApp::shaderUpdate ( )

protected

Update stock shader uniforms (MVP/MV/MVit) to current transforms.

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Member Data Documentation

glEnv

GLEnv GLApp::glEnv

protected

Window/context + platform utilities.

mv

Mat4 GLApp::mv

protected

Model‑view matrix used by stock shaders.

mvi

Mat4 GLApp::mvi

protected

Inverse of mv (for lighting helpers).

p

Mat4 GLApp::p

protected

Projection matrix used by stock shaders.

pointSprite

GLTexture2D GLApp::pointSprite

protected

Point‑sprite base texture.

pointSpriteHighlight

GLTexture2D GLApp::pointSpriteHighlight

protected

Optional highlight overlay sprite.

raster

GLTexture2D GLApp::raster

protected

Temporary texture for drawImage(Image).

resumeTime

double GLApp::resumeTime

protected

Timestamp used to keep animation time continuous on resume.

simpleArray

GLArray GLApp::simpleArray

protected

VAO used by helpers.

simpleHLSpriteProg

GLProgram GLApp::simpleHLSpriteProg

protected

Point sprite + highlight overlay.

simpleLightProg

GLProgram GLApp::simpleLightProg

protected

Lit shader (pos+color+normal).

simplePointProg

GLProgram GLApp::simplePointProg

protected

Point shader (pos+color), desktop uses glPointSize.

simpleProg

GLProgram GLApp::simpleProg

protected

Solid color shader (pos+color).

simpleSpriteProg

GLProgram GLApp::simpleSpriteProg

protected

Point sprite shader (pos+color+texture).

simpleTexProg

GLProgram GLApp::simpleTexProg

protected

Textured quad shader (pos+uv).

simpleVb

GLBuffer GLApp::simpleVb

protected

VBO used by helpers.

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The documentation for this class was generated from the following files:

• GLApp.h
• GLApp.cpp