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        前面几个案例通过TS传入点参数实现绘制，但是每次的绘制都是单独绘制一个点，未实现一次绘制多个点的效果。该案例通过GL的Buffer实现一次绘制多点。

1.知识点

1.1.缓冲区绘制流程

        通过缓冲区对象处理数据时，大概遵循以下5个步骤

2.代码

<script setup lang="ts">
    import { onMounted, ref } from "vue";
    import Gl2Utility from "../../Gl/Gl2Utility";
    import VertexBufferUtility from "../../Gl/VertexBufferUtility";

    const a_PositionName = "a_Position";

    onMounted(() => {



        const gl2 = Gl2Utility.GetGl2("canvas");

        if (gl2 == null) {
            console.error("初始化失败！");

            return;
        }



        //顶点着色器源码
        const vertexShaderSource = `

        attribute vec4 ${a_PositionName};

            void main(){

                //给内置变量gl_PointSize赋值像素大小
                 gl_PointSize=20.0;

                 //顶点位置，位于坐标原点
                  gl_Position =a_Position;
            }

        `;

        const fragShaderSource = `
            void main(){
                //定义片元颜色
                gl_FragColor = vec4(1.0,0.0,0.0,1.0);
            }
        `;


        const program = Gl2Utility.InitShaders(gl2, vertexShaderSource, fragShaderSource);

        if (program == null) {
            return;
        }
        //获取参数位置
        const a_PositionLocation = gl2.getAttribLocation(program, a_PositionName);

        if (a_PositionLocation < 0) {
            console.error("获取参数失败！");

            return;
        }


        const count = VertexBufferUtility.InitFloatXY(gl2, program, a_PositionName, [0.0, 0.5, -0.5, -0.5, 0.5, -0.5]);

        //设置清除时的背景色
        gl2.clearColor(0., 0., 0., 1.);

        //清除
        gl2.clear(gl2.COLOR_BUFFER_BIT);
       
        //绘制点
        gl2.drawArrays(gl2.POINTS, 0, count);
         

    });




</script>

<template>

    <div class="demo_main">

        <canvas id="canvas"></canvas>
    </div>
</template>

<style scoped>

    #canvas {
        width: 100%;
        height: 100%;
        margin: 0;
        padding: 0;
        background-color: blue;
    }

    .demo_main {
        width: 100%;
        height: 100%;
        margin: 0;
        padding: 0;
    }
</style>

3.效果