76 lines
2.4 KiB
Nim
76 lines
2.4 KiB
Nim
## This example show how to have real time pixie using glut API.
|
|
|
|
import math, opengl, opengl/glu, opengl/glut, pixie
|
|
|
|
let
|
|
w: int32 = 256
|
|
h: int32 = 256
|
|
|
|
var
|
|
screen = newImage(w, h)
|
|
ctx = newContext(screen)
|
|
frameCount = 0
|
|
|
|
proc display() {.cdecl.} =
|
|
## Called every frame by GLUT
|
|
|
|
# draw shiny sphere on gradient background
|
|
var linerGradient = Paint(kind: pkGradientLinear)
|
|
linerGradient.gradientHandlePositions.add(vec2(0, 0))
|
|
linerGradient.gradientHandlePositions.add(vec2(0, 256))
|
|
linerGradient.gradientStops.add(
|
|
ColorStop(color: rgbx(0, 0, 0, 255), position: 0))
|
|
linerGradient.gradientStops.add(
|
|
ColorStop(color: rgbx(255, 255, 255, 255), position: 1))
|
|
ctx.fillStyle = linerGradient
|
|
ctx.fillRect(0, 0, 256, 256)
|
|
|
|
var radialGradient = Paint(kind: pkGradientRadial)
|
|
radialGradient.gradientHandlePositions.add(vec2(128, 128))
|
|
radialGradient.gradientHandlePositions.add(vec2(256, 128))
|
|
radialGradient.gradientHandlePositions.add(vec2(128, 256))
|
|
radialGradient.gradientStops.add(
|
|
ColorStop(color: rgbx(255, 255, 255, 255), position: 0))
|
|
radialGradient.gradientStops.add(
|
|
ColorStop(color: rgbx(0, 0, 0, 255), position: 1))
|
|
ctx.fillStyle = radialGradient
|
|
ctx.fillCircle(vec2(128.0, 128.0 + sin(float(frameCount)/10.0) * 20), 76.8)
|
|
|
|
# update texture with new pixels from surface
|
|
var dataPtr = ctx.image.data[0].addr
|
|
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, GLsizei w, GLsizei h, GL_RGBA,
|
|
GL_UNSIGNED_BYTE, dataPtr)
|
|
|
|
# draw a quad over the whole screen
|
|
glClear(GL_COLOR_BUFFER_BIT)
|
|
glBegin(GL_QUADS)
|
|
glTexCoord2d(0.0, 0.0); glVertex2d(-1.0, +1.0)
|
|
glTexCoord2d(1.0, 0.0); glVertex2d(+1.0, +1.0)
|
|
glTexCoord2d(1.0, 1.0); glVertex2d(+1.0, -1.0)
|
|
glTexCoord2d(0.0, 1.0); glVertex2d(-1.0, -1.0)
|
|
glEnd()
|
|
glutSwapBuffers()
|
|
|
|
inc frameCount
|
|
|
|
glutPostRedisplay() # ask glut to draw next frame
|
|
|
|
glutInit()
|
|
glutInitDisplayMode(GLUT_DOUBLE)
|
|
glutInitWindowSize(w, h)
|
|
discard glutCreateWindow("GLUT/Pixie")
|
|
|
|
glutDisplayFunc(display)
|
|
loadExtensions()
|
|
|
|
# allocate a texture and bind it
|
|
var dataPtr = ctx.image.data[0].addr
|
|
glTexImage2D(GL_TEXTURE_2D, 0, 3, GLsizei w, GLsizei h, 0, GL_RGBA,
|
|
GL_UNSIGNED_BYTE, dataPtr)
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)
|
|
glEnable(GL_TEXTURE_2D)
|
|
|
|
glutMainLoop()
|