Kivy 自定义着色器触摸事件

Am using custom shader on my game, and i must because of performance. Now i am at the point where i want to bind touch events to my particles/Ufo so that i can decide what to do when someone touches them, but i don't know how i can calculate their width and height. I am currently able to tell where a touch event happened but my collide_point function always return False because i don't have the correct Width and Height of my game particle's. collide_point function require particle's right and top and particle's right and top requires particle's width and height to work. In the documentation it is said that

width 和 height 属性受布局逻辑影响

the width and the height property is subject to layout logic

但我没有使用任何 Layout，而是使用 Widget.如何计算我的游戏粒子的宽度和高度.下面是代码

but am not using any Layout, am using Widget instead. How can i calculate my game particle's width and height. Below is the code

from __future__ import division
from collections import namedtuple
import json
import math
import random
from kivy import platform
from kivy.app import App
from kivy.base import EventLoop
from kivy.clock import Clock
from kivy.core.image import Image
from kivy.core.window import Window
from kivy.graphics import Mesh
from kivy.graphics.instructions import RenderContext
from kivy.uix.widget import Widget
from kivy.utils import get_color_from_hex
import base64

UVMapping = namedtuple('UVMapping', 'u0 v0 u1 v1 su sv')

GLSL = """
---vertex
$HEADER$

attribute vec2  vCenter;
attribute float vScale;

void main(void)
{
    tex_coord0 = vTexCoords0;
    mat4 move_mat = mat4
        (1.0, 0.0, 0.0, vCenter.x,
         0.0, 1.0, 0.0, vCenter.y,
         0.0, 0.0, 1.0, 0.0,
         0.0, 0.0, 0.0, 1.0);
    vec4 pos = vec4(vPosition.xy * vScale, 0.0, 1.0)
        * move_mat;
    gl_Position = projection_mat * modelview_mat * pos;
}

---fragment
$HEADER$

void main(void)
{
    gl_FragColor = texture2D(texture0, tex_coord0);
}

"""

with open("game.glsl", "wb")  as glslc:
    glslc.write(GLSL)

def load_atlas():
    atlas = json.loads('''{"game-0.png": {"Elien": [2, 26, 100, 100]}}''') 

    tex_name, mapping = atlas.popitem()
    data = '''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'''
    with open(tex_name, "wb")  as co:
        co.write(base64.b64decode(data))
    tex = Image(tex_name).texture
    tex_width, tex_height = tex.size

    uvmap = {}
    for name, val in mapping.items():
        x0, y0, w, h = val
        x1, y1 = x0 + w, y0 + h
        uvmap[name] = UVMapping(
            x0 / tex_width, 1 - y1 / tex_height,
            x1 / tex_width, 1 - y0 / tex_height,
            0.5 * w, 0.5 * h)

    return tex, uvmap


class Particle:
    x = 0
    y = 0
    size = 1

    def __init__(self, parent, i):
        self.parent = parent
        self.vsize = parent.vsize
        self.base_i = 4 * i * self.vsize
        self.reset(created=True)

    def update(self):
        for i in range(self.base_i,
                       self.base_i + 4 * self.vsize,
                       self.vsize):
            self.parent.vertices[i:i + 3] = (
                self.x, self.y, self.size)

    def reset(self, created=False):
        raise NotImplementedError()

    def advance(self, nap):
        raise NotImplementedError()


class GameScreen(Widget):
    indices = []
    vertices = []
    particles = []

    def __init__(self, **kwargs):
        Widget.__init__(self, **kwargs)
        self.canvas = RenderContext(use_parent_projection=True)
        self.canvas.shader.source = "game.glsl"

        self.vfmt = (
            (b'vCenter', 2, 'float'),
            (b'vScale', 1, 'float'),
            (b'vPosition', 2, 'float'),
            (b'vTexCoords0', 2, 'float'),
        )

        self.vsize = sum(attr[1] for attr in self.vfmt)
        self.texture, self.uvmap = load_atlas()

    def on_touch_down(self, touch):
        for w in self.particles:
            if w.collide_point(*touch.pos):
                w.reset() #Not Working
        return super(GameScreen, self).on_touch_down(touch) 

    def on_touch_move(self, touch):
        for w in self.particles:
            if w.collide_point(*touch.pos):
                w.reset() #Not Working
        return super(GameScreen, self).on_touch_move(touch) 

    def make_particles(self, Ap, num):
        count = len(self.particles)
        uv = self.uvmap[Ap.tex_name]

        for i in range(count, count + num):
            j = 4 * i
            self.indices.extend((
                j, j + 1, j + 2, j + 2, j + 3, j))

            self.vertices.extend((
                0, 0, 1, -uv.su, -uv.sv, uv.u0, uv.v1,
                0, 0, 1,  uv.su, -uv.sv, uv.u1, uv.v1,
                0, 0, 1,  uv.su,  uv.sv, uv.u1, uv.v0,
                0, 0, 1, -uv.su,  uv.sv, uv.u0, uv.v0,
            ))

            p = Ap(self, i)
            self.particles.append(p)

    def update_glsl(self, nap):
        for p in self.particles:
            p.advance(nap)
            p.update()

        self.canvas.clear()

        with self.canvas:
            Mesh(fmt=self.vfmt, mode='triangles',
                 indices=self.indices, vertices=self.vertices,
                 texture=self.texture)

class Ufo(Particle):
    plane = 2.0
    tex_name = 'Elien' 
    texture_size = 129
    right = top = 129

    def reset(self, created=False):
        self.plane = random.uniform(2.0, 2.8)
        self.x = random.randint(15, self.parent.right-15)
        self.y = self.parent.top+random.randint(100, 2500)
        self.size = random.uniform(0.5, 1.0) #every particle must have a random size
        self.top = self.size * self.texture_size 
        self.right = self.size * self.texture_size 

    def collide_point(self, x, y):
        '''Check if a point (x, y) is inside the Ufo's axis aligned bounding box.'''
        with open('TouchFeedback.txt', 'wb') as c:
            c.write(str(x)+', '+str(y)) 

        return self.x <= x <= self.right and self.y <= y <= self.top

    def advance(self, nap):
        self.y -= 100 * self.plane * nap
        if self.y < 0:
            self.reset()

class Game(GameScreen):
    def initialize(self):
        self.make_particles(Ufo, 20)

    def update_glsl(self, nap):
        GameScreen.update_glsl(self, nap)

class GameApp(App):
    def build(self):
        EventLoop.ensure_window()
        return Game()

    def on_start(self):
        self.root.initialize()
        Clock.schedule_interval(self.root.update_glsl, 60 ** -1)

if __name__ == '__main__':
    Window.clearcolor = get_color_from_hex('111110')
    GameApp().run()

推荐答案

我认为你没有计算/更新 Ufo 的 top 和 right 属性 对象.此外，由于您的 GL 代码将 (x,y) 视为您的圆心，但 Kivy 认为 (x,y) 要成为对象的左下角，您需要牢记这一点.为了正确计算 collide_point()，我在您的 Ufo 中添加了 left 和 bottom 属性，并使用这些属性来计算碰撞.以下是包含这些更改的代码的更新版本:

I think you are not calculating/updating your top and right properties of your Ufo objects. Also, since your GL code considers (x,y) to be the center of your circle, but Kivy considers (x,y) to be the lower left corner of an object, you need to keep that in mind. In order to correctly calculate collide_point(), I have added left and bottom properties to your Ufo, and use those properties to calculate collisions. Here is an updated version of your code with those changes:

from __future__ import division
import kivy
from kivy.config import Config
from kivy.graphics.context_instructions import Color
from kivy.graphics.vertex_instructions import Rectangle
from kivy.lang import Builder

Config.set('modules', 'monitor', '')


from collections import namedtuple
import json
import math
import random
from kivy import platform
from kivy.app import App
from kivy.base import EventLoop
from kivy.clock import Clock
from kivy.core.image import Image
from kivy.core.window import Window
from kivy.event import EventDispatcher
from kivy.graphics import Mesh
from kivy.graphics.instructions import RenderContext
from kivy.properties import NumericProperty
from kivy.uix.widget import Widget
from kivy.utils import get_color_from_hex
import base64

UVMapping = namedtuple('UVMapping', 'u0 v0 u1 v1 su sv')

GLSL = """
---vertex
$HEADER$

attribute vec2  vCenter;
attribute float vScale;

void main(void)
{
    tex_coord0 = vTexCoords0;
    mat4 move_mat = mat4
        (1.0, 0.0, 0.0, vCenter.x,
         0.0, 1.0, 0.0, vCenter.y,
         0.0, 0.0, 1.0, 0.0,
         0.0, 0.0, 0.0, 1.0);
    vec4 pos = vec4(vPosition.xy * vScale, 0.0, 1.0)
        * move_mat;
    gl_Position = projection_mat * modelview_mat * pos;
}

---fragment
$HEADER$

void main(void)
{
    gl_FragColor = texture2D(texture0, tex_coord0);
}

"""

with open("game.glsl", "wb")  as glslc:
    glslc.write(GLSL.encode())

def load_atlas():
    atlas = json.loads('''{"game-0.png": {"Elien": [2, 26, 100, 100]}}''')

    tex_name, mapping = atlas.popitem()
    data = '''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'''
    with open(tex_name, "wb")  as co:
        co.write(base64.b64decode(data))
    tex = Image(tex_name).texture
    tex_width, tex_height = tex.size

    uvmap = {}
    for name, val in mapping.items():
        x0, y0, w, h = val
        x1, y1 = x0 + w, y0 + h
        uvmap[name] = UVMapping(
            x0 / tex_width, 1 - y1 / tex_height,
            x1 / tex_width, 1 - y0 / tex_height,
            0.5 * w, 0.5 * h)

    return tex, uvmap


class Particle(EventDispatcher):
    # x = 0
    # y = 0
    x = NumericProperty(0)
    y = NumericProperty(0)
    size = 1

    def __init__(self, parent, i):
        super(Particle, self).__init__()
        self.parent = parent
        self.vsize = parent.vsize
        self.base_i = 4 * i * self.vsize
        self.reset(created=True)

    def update(self):
        for i in range(self.base_i,
                       self.base_i + 4 * self.vsize,
                       self.vsize):
            self.parent.vertices[i:i + 3] = (
                self.x, self.y, self.size)

    def reset(self, created=False):
        raise NotImplementedError()

    def advance(self, nap):
        raise NotImplementedError()


class GameScreen(Widget):
    indices = []
    vertices = []
    particles = []

    def __init__(self, **kwargs):
        Widget.__init__(self, **kwargs)
        self.canvas = RenderContext(use_parent_projection=True)
        self.canvas.shader.source = "game.glsl"

        self.vfmt = (
            (b'vCenter', 2, 'float'),
            (b'vScale', 1, 'float'),
            (b'vPosition', 2, 'float'),
            (b'vTexCoords0', 2, 'float'),
        )

        self.vsize = sum(attr[1] for attr in self.vfmt)
        self.texture, self.uvmap = load_atlas()

    def on_touch_down(self, touch):
        for w in self.particles:
            if w.collide_point(*touch.pos):
                w.reset() #Not Working
        return super(GameScreen, self).on_touch_down(touch)

    def on_touch_move(self, touch):
        for w in self.particles:
            if w.collide_point(*touch.pos):
                w.reset() #Not Working
        return super(GameScreen, self).on_touch_move(touch)

    def make_particles(self, Ap, num):
        count = len(self.particles)
        uv = self.uvmap[Ap.tex_name]

        for i in range(count, count + num):
            j = 4 * i
            self.indices.extend((
                j, j + 1, j + 2, j + 2, j + 3, j))

            self.vertices.extend((
                0, 0, 1, -uv.su, -uv.sv, uv.u0, uv.v1,
                0, 0, 1,  uv.su, -uv.sv, uv.u1, uv.v1,
                0, 0, 1,  uv.su,  uv.sv, uv.u1, uv.v0,
                0, 0, 1, -uv.su,  uv.sv, uv.u0, uv.v0,
            ))

            p = Ap(self, i)
            self.particles.append(p)

    def update_glsl(self, nap):
        for p in self.particles:
            p.advance(nap)
            p.update()

        self.canvas.clear()
        self.canvas.before.clear()  # temporary

        with self.canvas.before:  # temporary code block
            for p in self.particles:
                Rectangle(pos=(p.left, p.bottom), size=(p.size*p.texture_size, p.size*p.texture_size))

        with self.canvas:
            Mesh(fmt=self.vfmt, mode='triangles',
                 indices=self.indices, vertices=self.vertices,
                 texture=self.texture)


class Ufo(Particle):
    plane = 2.0
    tex_name = 'Elien'
    texture_size = 129
    right = NumericProperty(129)
    top = NumericProperty(129)
    left = NumericProperty(0)
    bottom = NumericProperty(0)

    def reset(self, created=False):
        self.plane = random.uniform(2.0, 2.8)
        self.size = random.uniform(0.5, 1.0) #every particle must have a random size
        self.x = random.randint(15, self.parent.right-15)
        self.y = self.parent.top+random.randint(100, 2500)

    def collide_point(self, x, y):
        '''Check if a point (x, y) is inside the Ufo's axis aligned bounding box.'''
        return self.left <= x <= self.right and self.bottom <= y <= self.top

    def advance(self, nap):
        self.y -= 100 * self.plane * nap
        if self.y < 0:
            self.reset()

    def on_x(self, instance, new_x):
        self.right = new_x + self.size * self.texture_size / 2.0
        self.left = new_x - self.size * self.texture_size / 2.0

    def on_y(self, instance, new_y):
        self.top = new_y + self.size * self.texture_size / 2.0
        self.bottom = new_y - self.size * self.texture_size / 2.0

class Game(GameScreen):
    def initialize(self):
        self.make_particles(Ufo, 20)

    def update_glsl(self, nap):
        GameScreen.update_glsl(self, nap)

class GameApp(App):
    def build(self):
        EventLoop.ensure_window()
        return Game()

    def on_start(self):
        self.root.initialize()
        Clock.schedule_interval(self.root.update_glsl, 60 ** -1)

if __name__ == '__main__':
    Window.clearcolor = get_color_from_hex('111110')
    GameApp().run()

我还添加了使用 canvas.before 绘制 Ufo 边界框.这只是为了可视化每个 Ufo 的 clickable 区域，并且可以轻松移除.

I have also adding drawing the Ufo bounding box using canvas.before. This is just to visualize the clickable area for each Ufo, and can be easily removed.

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