Drawing a Point Without Buffers

This JavaScript program demonstrates how draw a point without using a buffer in a WebGL program.

DrawAPointWithoutBuffers.html

<!DOCTYPE html>
<html>
  <head>
    <title>XoaX.net's WebGL</title>
    <script  id="idVertexShader" type="c">
      void main() {
        gl_Position = vec4(0.5, .2, 0.0, 1.0);
        gl_PointSize = 25.0;
      }
    </script>

    <script  id="idFragmantShader" type="c">
      void main() {
        gl_FragColor = vec4(1.0, 0.2, 0.2, 1.0);
      }
    </script>
  </head>
  <body onload="Render()">
    <script>
      function Render() {
        // Get A WebGL context
        var qCanvas = document.querySelector("#idWebGL");
        var qGL = qCanvas.getContext("webgl");
        qGL.clearColor(0.85, 0.95, 0.95, 1.0);
        qGL.clear(qGL.COLOR_BUFFER_BIT);

        // The Vertex Shader
        var sVertextShaderCode = document.querySelector("#idVertexShader").text;
        var qVertexShader = qGL.createShader(qGL.VERTEX_SHADER);
        qGL.shaderSource(qVertexShader, sVertextShaderCode);
        qGL.compileShader(qVertexShader);

        // The Fragment Shader
        var sFragShaderCode = document.querySelector("#idFragmantShader").text;
        var qFragmentShader = qGL.createShader(qGL.FRAGMENT_SHADER);
        qGL.shaderSource(qFragmentShader, sFragShaderCode);
        qGL.compileShader(qFragmentShader);

        // Compile and link the program
        var qProgram = qGL.createProgram();
        qGL.attachShader(qProgram, qVertexShader);
        qGL.attachShader(qProgram, qFragmentShader);
        qGL.linkProgram(qProgram);

        // Deallocate
        qGL.detachShader(qProgram, qVertexShader);
        qGL.detachShader(qProgram, qFragmentShader);
        qGL.deleteShader(qVertexShader);
        qGL.deleteShader(qFragmentShader);

        qGL.useProgram(qProgram);
        qGL.drawArrays(qGL.POINTS, 0, 1);

        // Deallocate
        qGL.useProgram(null);
        if (qProgram) qGL.deleteProgram(qProgram);
      }
    </script>
    <canvas id="idWebGL" width="400", height="400" style="border:1px solid #444444"></canvas>
  </body>
</html>

WebGL JavaScript

Drawing a Point Without Buffers

DrawAPointWithoutBuffers.html

Output