Question

因为我需要显示huge number of labels move independently，我需要在pyglet中为纹理渲染一个标签（否则更新每个字形的顶点列表太慢）。

我有一个解决方案来做到这一点，但我的问题是包含字形的纹理是黑色的，但我希望它是红色的。请参阅以下示例：

from pyglet.gl import *

def label2texture(label):
    vertex_list = label._vertex_lists[0].vertices[:]
    xpos = map(int, vertex_list[::8])
    ypos = map(int, vertex_list[1::8])
    glyphs = label._get_glyphs()

    xstart = xpos[0]
    xend = xpos[-1] + glyphs[-1].width
    width = xend - xstart

    ystart = min(ypos)
    yend = max(ystart+glyph.height for glyph in glyphs)
    height = yend - ystart

    texture = pyglet.image.Texture.create(width, height, pyglet.gl.GL_RGBA)

    for glyph, x, y in zip(glyphs, xpos, ypos):
        data = glyph.get_image_data()
        x = x - xstart
        y =  height - glyph.height - y + ystart
        texture.blit_into(data, x, y, 0)

    return texture.get_transform(flip_y=True)

window = pyglet.window.Window()
label = pyglet.text.Label('Hello World!', font_size = 36)
texture = label2texture(label)

@window.event
def on_draw():
    hoff = (window.width / 2) - (texture.width / 2)
    voff = (window.height / 2) - (texture.height / 2)

    glClear(GL_COLOR_BUFFER_BIT)
    glEnable(GL_BLEND)
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
    glClearColor(0.0, 1.0, 0.0, 1.0)
    window.clear()
    glEnable(GL_TEXTURE_2D);

    glBindTexture(GL_TEXTURE_2D, texture.id)
    glColor4f(1.0, 0.0, 0.0, 1.0) #I'd like the font to be red
    glBegin(GL_QUADS);
    glTexCoord2d(0.0,1.0); glVertex2d(hoff,voff);
    glTexCoord2d(1.0,1.0); glVertex2d(hoff+texture.width,voff);
    glTexCoord2d(1.0,0.0); glVertex2d(hoff+texture.width,voff+texture.height);
    glTexCoord2d(0.0,0.0); glVertex2d(hoff, voff+texture.height);
    glEnd();

pyglet.app.run()

我知道如何为此着色吗？

Answer 1

您想要设置glEnable(GL_COLOR_MATERIAL)。这使得纹理颜色与当前的OpenGL颜色混合。您还可以使用glColorMaterial函数指定是否应影响每个多边形的前/后/两者。文档here。

Answer 2

通过glTexEnv()使用贴花时不是吗？

opengl用顶点颜色设置纹理颜色

2 个答案: