// Entry point of program
func main() {
// Creates the Window Wrapper
glw := wrapper.NewWrapper(windowWidth, windowHeight, "Lab 3: Lights")
glw.SetFPS(windowFPS)
// Creates the Window
glw.CreateWindow()
// Sets the Event Callbacks
glw.SetRenderCallback(drawLoop)
glw.SetKeyCallBack(keyCallback)
glw.SetReshapeCallback(reshape)
// Initializes the App
InitApp(glw)
// Starts the Rendering Loop
glw.StartLoop()
// Sets the Viewport (Important !!, this has to run after the loop!!)
defer gl.Viewport(0, 0, windowWidth, windowHeight)
}
//
// Reshape
// This gets called when the window changes its size
//
// @param window (*glfw.Window) a pointer to the window
// @param width (int) the width of the window
// @param height (int) the height of the window
//
func reshape(window *glfw.Window, width, height int) {
gl.Viewport(0, 0, int32(width), int32(height))
aspect_ratio = (float32(width) / 640.0 * 4.0) / (float32(height) / 480.0 * 3.0)
}
func render(w *glfw.Window, r *gResources) {
width, height := w.GetFramebufferSize()
ratio := float32(width) / float32(height)
var xmul, ymul float32
if ratio > 1 {
xmul, ymul = ra/ratio, ra
} else {
xmul, ymul = ra, ra*ratio
}
d := time.Since(start).Seconds()
sin := float32(math.Sin(d))
cos := float32(math.Cos(d))
gl.Viewport(0, 0, int32(width), int32(height))
gl.Clear(gl.COLOR_BUFFER_BIT)
////////////////
// axes
gl.UseProgram(r.program1)
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer1)
gl.VertexAttribPointer(
uint32(r.attributes1.position), // attribute
2, // size
gl.FLOAT, // type
false, // normalized?
8, // stride
gl.PtrOffset(0)) // array buffer offset
gl.EnableVertexAttribArray(uint32(r.attributes1.position))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer1)
gl.LineWidth(1)
gl.DrawElements(
gl.LINES, // mode
4, // count
gl.UNSIGNED_INT, // type
gl.PtrOffset(0)) // element array buffer offset
gl.DisableVertexAttribArray(uint32(r.attributes1.position))
////////////////
// triangle
gl.UseProgram(r.program2)
gl.Uniform1f(r.uniforms2.xmul, xmul)
gl.Uniform1f(r.uniforms2.ymul, ymul)
gl.Uniform1f(r.uniforms2.sin, sin)
gl.Uniform1f(r.uniforms2.cos, cos)
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer2)
gl.VertexAttribPointer(
uint32(r.attributes2.position), // attribute
2, // size
gl.FLOAT, // type
false, // normalized?
8, // stride
gl.PtrOffset(0)) // array buffer offset
gl.EnableVertexAttribArray(uint32(r.attributes2.position))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer2)
gl.EnableVertexAttribArray(uint32(r.attributes2.color))
gl.BindBuffer(gl.ARRAY_BUFFER, r.colorBuffer2)
gl.VertexAttribPointer(
uint32(r.attributes2.color), // attribute
3, // size
gl.FLOAT, // type
false, // normalized?
0, // stride
gl.PtrOffset(0)) // array buffer offset
gl.DrawElements(
gl.TRIANGLES, // mode
3, // count
gl.UNSIGNED_INT, // type
gl.PtrOffset(0)) // element array buffer offset
////////////////
// circle
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer3)
gl.VertexAttribPointer(
uint32(r.attributes2.position), // attribute
2, // size
gl.FLOAT, // type
false, // normalized?
8, // stride
gl.PtrOffset(0)) // array buffer offset
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer3)
gl.BindBuffer(gl.ARRAY_BUFFER, r.colorBuffer3)
gl.VertexAttribPointer(
uint32(r.attributes2.color), // attribute
3, // size
gl.FLOAT, // type
false, // normalized?
0, // stride
gl.PtrOffset(0)) // array buffer offset
gl.LineWidth(5)
gl.DrawElements(
gl.LINE_LOOP, // mode
r.len3, // count
gl.UNSIGNED_INT, // type
gl.PtrOffset(0)) // element array buffer offset
gl.DisableVertexAttribArray(uint32(r.attributes2.color))
gl.DisableVertexAttribArray(uint32(r.attributes2.position))
}