my minimal code:
from OpenGL.GLUT import *
from OpenGL.GLU import *
from OpenGL.GL import *
from PIL import Image
from PIL import ImageDraw
import numpy
rotate=[33,40,20]
block_VAO=0
draw=False
block_EBO_buffer_len=0
texture_VBO=0
def create_block_texture():
block=Image.new("RGB",(100,100),"white")
draw=ImageDraw.Draw(block)
draw.line([5,5,5,95,95,95,95,5,5,5],(0,255,0),10)
pixels=block.load()
all_pixels=[]
for x in range(100):
for y in range(100):all_pixels+=list(pixels[x,y])
return bytes(all_pixels)
def create_blocks(x: int,y: int,z: int):
global draw,block_VAO,block_EBO_buffer_len,texture_VBO
if draw:
return
draw=True
block_point_buffer=[]
block_color_buffer=[]
block_EBO_buffer=[]
block_point_buffer+=[x-0.5,y+0.5,z-0.5, #V0
x+0.5,y+0.5,z-0.5, #V1
x+0.5,y-0.5,z-0.5, #V2
x-0.5,y-0.5,z-0.5, #V3
x-0.5,y+0.5,z+0.5, #V4
x+0.5,y+0.5,z+0.5, #V5
x+0.5,y-0.5,z+0.5, #V6
x-0.5,y-0.5,z+0.5] #V7
block_EBO_buffer+=[0,1,5,4,
3,2,6,7,
0,3,7,4,
1,2,6,5,
0,1,2,3,
4,5,6,7]
block_color_buffer+=[1.0,0.0,1.0,1.0]*8
texture_VBO=glGenTextures(1)
glBindTexture(GL_TEXTURE_2D,texture_VBO)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR)
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,100,100,0,GL_RGB,GL_UNSIGNED_BYTE,create_block_texture())
glGenerateMipmap(GL_TEXTURE_2D)
glBindTexture(GL_TEXTURE_2D,0)
texture_EBO=glGenBuffers(1)
texture_coord=[
0.0,1.0,
1.0,1.0,
1.0,0.0,
0.0,0.0,
0.0,0.0
]
glBindBuffer(GL_ARRAY_BUFFER,texture_EBO)
a=numpy.array(texture_coord,dtype='float32')
glBufferData(GL_ARRAY_BUFFER,sys.getsizeof(a),a,GL_STATIC_DRAW)
block_VBO=glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER,block_VBO)
a=numpy.array(block_point_buffer,dtype='float32')
glBufferData(GL_ARRAY_BUFFER,sys.getsizeof(a),a,GL_STATIC_DRAW)
color_VBO=glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER,color_VBO)
a=numpy.array(block_color_buffer,dtype='float32')
glBufferData(GL_ARRAY_BUFFER,sys.getsizeof(a),a,GL_STATIC_DRAW)
block_VAO=glGenVertexArrays(1)
glBindVertexArray(block_VAO)
block_EBO=glGenBuffers(1)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,block_EBO)
a=numpy.array(block_EBO_buffer,dtype='uint32')
glBufferData(GL_ELEMENT_ARRAY_BUFFER,sys.getsizeof(a),a,GL_STATIC_DRAW)
block_EBO_buffer_len=len(a)
glBindBuffer(GL_ARRAY_BUFFER,block_VBO)
glVertexPointer(3,GL_FLOAT,0,None)
glEnableClientState(GL_VERTEX_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER,color_VBO)
glColorPointer(4,GL_FLOAT,0,None)
glEnableClientState(GL_COLOR_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER,texture_EBO)
glTexCoordPointer(2,GL_FLOAT,0,None)
glEnableClientState(GL_TEXTURE_COORD_ARRAY)
glBindVertexArray(0)
def display():
glMatrixMode(GL_MODELVIEW)
glClear(GL_COLOR_BUFFER_BIT)
glLoadIdentity()
glTranslatef(0,0,-4.5)
glRotatef(rotate[0],1,0.0,0)
glRotatef(rotate[1],0,1,0)
glRotatef(rotate[2],0,0,1)
glScalef(1,1,1)
glBindVertexArray(block_VAO)
glBindTexture(GL_TEXTURE_2D,texture_VBO)
glDrawElements(GL_QUADS,block_EBO_buffer_len,GL_UNSIGNED_INT,None)
glBindVertexArray(0)
rotate[1]+=0.1
glutSwapBuffers()
glutPostRedisplay()
def reshape(width,height):
glViewport(0,0,width,height)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(40.0,width/height,0.5,20.0)
glMatrixMode(GL_MODELVIEW)
glutInit(sys.argv)
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB)
glutInitWindowSize(400,350)
glutCreateWindow(b"OpenGL Window")
create_blocks(0,0,0)
glClearColor(0.0,0.0,0.0,0.0)
glutDisplayFunc(display)
glutReshapeFunc(reshape)
glutMainLoop()
It should draw a cube with green border,but it just drew a pink cube(glColorPointer did it) with no green border.I tried many ways to do it,but it always can't follow my mind.Please answer with a minimal example based on my original code!⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
When using legacy OpenGL, two-dimensional texturing must be enabled befor drawing the geometry:
glEnable(GL_TEXTURE_2D)
This sets a global state. So if you want to draw subsequent geometry without texture, you need to turn it off again:
glDisable(GL_TEXTURE_2D)
It should be mentioned that by default the texture color is modulated with the current color. So it makes sense to use a white color before drawing an object with a texture. Likewise you can change the environment mode to GL_REPLACE
, instead:
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);