如何绘制元素？

Question

我正在使用 Python、Modern OpenGL 和 GLFW 开发游戏，是的，我知道这更难，但我喜欢编程，即使那样也可以。到目前为止游戏的性能非常好，FPS 在每秒 90 到 100 帧之间，但在游戏的某个时刻我不得不在游戏的不同区域同时绘制几个不同的对象，那一刻 FPS 下降到 30到 40 因为数量，没什么太严重的，但我仍然不希望这种下降发生所以按照网站上的教程：https://open.gl/drawing 我尝试使用 glDrawElements 尝试一次绘制所有内容，但之前为了在我的游戏中实现这一点，我决定在一个更简单的程序中对其进行测试，但它最终无法正常工作，代码运行但没有任何显示，有人知道我做错了什么吗？

import glfw, time, ctypes, math, pyrr
import numpy as np
from OpenGL.GL import *
from OpenGL.GL.shaders import *

glfw.init()

glfw.window_hint(glfw.SAMPLES, 4)

w = glfw.create_window(640, 480, "Galeria das Sombras", None, None)

glfw.make_context_current(w)

v = """
#version 330
in layout(location=0) vec3 posicao;
in layout(location=1) vec2 textura;
uniform mat4 view;
uniform vec3 def;
uniform vec3 pos;
uniform vec3 scale;
uniform float giro;
uniform float giro2;
out vec2 texcords;
void main(){
    texcords = textura;
    vec3 p = vec3(posicao.x*scale.x,posicao.y*scale.y,posicao.z*scale.z);
    p = p+def;
    p = vec3(-sin(giro)*p.z+cos(giro)*p.x,p.y,sin(giro)*p.x+cos(giro)*p.z);
    p = vec3(p.x,-sin(giro2)*p.z+cos(giro2)*p.y,sin(giro2)*p.y+cos(giro2)*p.z);
    p = p+pos;
    gl_Position = view*vec4(p,1);
}
"""

f = """
#version 330
in vec2 texcords;
uniform vec3 cor;
uniform sampler2D texinfo;
void main(){
    gl_FragColor = vec4(cor,1)*texture(texinfo,texcords);
}
"""

shader = compileProgram(compileShader(v,GL_VERTEX_SHADER),compileShader(f,GL_FRAGMENT_SHADER))

tudo = [-1,-1,0,0,1,
        1,-1,0,1,1,
        1,1,0,1,0,
        -1,1,0,0,0]

tudo = np.array(tudo, np.float32)

VBO = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, VBO)
glBufferData(GL_ARRAY_BUFFER, len(tudo)*4, tudo, GL_STATIC_DRAW)

glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 20, ctypes.c_void_p(0))
glEnableVertexAttribArray(0)

glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 20, ctypes.c_void_p(12))
glEnableVertexAttribArray(1)

tudo = [0,1,2,
        1,2,3]

tudo = np.array(tudo, np.float32)

VBE = glGenBuffers(1)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, VBE)
glBufferData(GL_ELEMENT_ARRAY_BUFFER, len(tudo)*4, tudo, GL_STATIC_DRAW)

glUseProgram(shader)

view = pyrr.matrix44.create_perspective_projection_matrix(60, 640/480, .1, 1000)
p = glGetUniformLocation(shader, "view")
glUniformMatrix4fv(p, 1, GL_FALSE, view)

glEnable(GL_DEPTH_TEST)
glEnable(GL_MULTISAMPLE)
glEnable(GL_TEXTURE_2D)

from PIL import Image

t = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, t)
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_NEAREST)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
buffer = Image.open("p.jpg")
data = buffer.tobytes()
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, buffer.size[0], buffer.size[1], 0, GL_RGB, GL_UNSIGNED_BYTE, data)

girar = 0
tempo = glfw.get_time()
tfps = glfw.get_time()
fps = 0
action = 0

while not glfw.window_should_close(w):
    glfw.swap_buffers(w)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    view = pyrr.matrix44.create_perspective_projection_matrix(60, glfw.get_window_size(w)[0]/glfw.get_window_size(w)[1], .1, 1000)
    p = glGetUniformLocation(shader, "view")
    glUniformMatrix4fv(p, 1, GL_FALSE, view)
    glViewport(0,0,glfw.get_window_size(w)[0],glfw.get_window_size(w)[1])
    p = glGetUniformLocation(shader, "cor")
    glUniform3f(p, 1, 0, 0)
    p = glGetUniformLocation(shader, "def")
    glUniform3f(p, 0, 0, 0)
    p = glGetUniformLocation(shader, "scale")
    glUniform3f(p, 1, 1, 1)
    p = glGetUniformLocation(shader, "giro")
    glUniform1f(p, girar*math.pi/180)
    if glfw.get_time() - tempo > 1/60:
        girar+=1
        tempo = glfw.get_time()
        if action > 0:
            action-=.05
        if action < 0:
            action = 0
    p = glGetUniformLocation(shader, "giro2")
    if glfw.get_key(w, glfw.KEY_W) and action == 0:
        action = 2
    if action > 1:
        glUniform1f(p, (1-(action-1))*-90*(math.pi/180))
    else:
        glUniform1f(p, action*-90*(math.pi/180))
    p = glGetUniformLocation(shader, "pos")
    glUniform3f(p, 0, 0, -10)
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0)
    # glDrawArrays(GL_QUADS, 0, 4)
    fps+=1
    if glfw.get_time() - tfps > 1:
        print("FPS:",fps)
        fps = 0
        tfps = glfw.get_time()
    glfw.poll_events()
    time.sleep(1/240)

glfw.destroy_window(w)
glfw.terminate()

Answer 1

索引数组的数据类型必须是整数。类型必须对应于绘图调用中的类型规范

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0)

使用 np.uint32 而不是 np.float32 作为 GL_ELEMENT_ARRAY_BUFFER:

~~tudo = np.array(tudo, np.float32)~~

tudo = np.array(tudo, np.uint32)

glDrawElements最后一个参数的类型是指针(c_void_p):

~~glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0)~~

两者都

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, ctypes.c_void_p(0))

或

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, None)

另外，你的索引是错误的：

~~tudo = [0,1,2, 1,2,3]~~

tudo = [0,1,2, 0,2,3]

如何绘制元素？

How to draw the elements?

python

opengl

glfw