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The fastest way to batch calls in WebGL

I am trying to rewrite my canvas-based rendering for my 2nd game engine. I have achieved good results and handle textures fine in a webgl context, including scaling, rotation, and blending. But my job sucks. On my test laptop, I can get 30 frames per second in 2d vanilla with 1000 objects on the screen at the same time; in WebGL I get 30 frames per second with 500 objects on the screen. I expect the situation to be reversed!

I have a suspicious suspicion that all this buffer garbage Float32Arraythat I throw is the culprit . Here is my render code:

// boilerplate code and obj coordinates

// grab gl context
var canvas = sys.canvas;
var gl = sys.webgl;
var program = sys.glProgram;

// width and height
var scale = sys.scale;
var tileWidthScaled = Math.floor(tileWidth * scale);
var tileHeightScaled = Math.floor(tileHeight * scale);
var normalizedWidth = tileWidthScaled / this.width;
var normalizedHeight = tileHeightScaled / this.height;

var worldX = targetX * scale;
var worldY = targetY * scale;

this.bindGLBuffer(gl, this.vertexBuffer, sys.glWorldLocation);
this.bufferGLRectangle(gl, worldX, worldY, tileWidthScaled, tileHeightScaled);

gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this.texture);

var frameX = (Math.floor(tile * tileWidth) % this.width) * scale;
var frameY = (Math.floor(tile * tileWidth / this.width) * tileHeight) * scale;

// fragment (texture) shader
this.bindGLBuffer(gl, this.textureBuffer, sys.glTextureLocation);
this.bufferGLRectangle(gl, frameX, frameY, normalizedWidth, normalizedHeight);

gl.drawArrays(gl.TRIANGLES, 0, 6);

bufferGLRectangle: function (gl, x, y, width, height) {
    var left = x;
    var right = left + width;
    var top = y;
    var bottom = top + height;
    gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
        left, top,
        right, top,
        left, bottom,
        left, bottom,
        right, top,
        right, bottom
    ]), gl.STATIC_DRAW);
},

bindGLBuffer: function (gl, buffer, location) {
    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
    gl.vertexAttribPointer(location, 2, gl.FLOAT, false, 0, 0);
},

And here are my simple test shaders (they lack mixing, scaling and rotation):

// fragment (texture) shader
precision mediump float;
uniform sampler2D image;
varying vec2 texturePosition;

void main() {
    gl_FragColor = texture2D(image, texturePosition);
}

// vertex shader
attribute vec2 worldPosition;
attribute vec2 vertexPosition;

uniform vec2 canvasResolution;
varying vec2 texturePosition;

void main() {
    vec2 zeroToOne = worldPosition / canvasResolution;
    vec2 zeroToTwo = zeroToOne * 2.0;
    vec2 clipSpace = zeroToTwo - 1.0;

    gl_Position = vec4(clipSpace * vec2(1, -1), 0, 1);
    texturePosition = vertexPosition;
}

, ? drawArrays? ?

!

+5
2

, .

Float32Arrays, ( ). :

verts[0] = left; verts[1] = top;
verts[2] = right; verts[3] = top;
// etc... 
gl.bufferData(gl.ARRAY_BUFFER, verts, gl.STATIC_DRAW);

, , . 3D API . , , drawArrays/drawElements, .

, - , , . psuedocode:

var MAX_QUADS_PER_BATCH = 100;
var VERTS_PER_QUAD = 6;
var FLOATS_PER_VERT = 2;
var verts = new Float32Array(MAX_QUADS_PER_BATCH * VERTS_PER_QUAD * FLOATS_PER_VERT);

var quadCount = 0;
function addQuad(left, top, bottom, right) {
    var offset = quadCount * VERTS_PER_QUAD * FLOATS_PER_VERT;

    verts[offset] = left; verts[offset+1] = top;
    verts[offset+2] = right; verts[offset+3] = top;
    // etc...

    quadCount++;

    if(quadCount == MAX_QUADS_PER_BATCH) {
        flushQuads();
    }
}

function flushQuads() {
    gl.bindBuffer(gl.ARRAY_BUFFER, vertsBuffer);
    gl.bufferData(gl.ARRAY_BUFFER, verts, gl.STATIC_DRAW); // Copy the buffer we've been building to the GPU.

    // Make sure vertexAttribPointers are set, etc...

    gl.drawArrays(gl.TRIANGLES, 0, quadCount + VERTS_PER_QUAD);
}

// In your render loop

for(sprite in spriteTypes) {
    gl.bindTexture(gl.TEXTURE_2D, sprite.texture);

    for(instance in sprite.instances) {
        addQuad(instance.left, instance.top, instance.right, instance.bottom);  
    }

    flushQuads();
}

, , , , , .

+7

WebGL Inspector, , GL ( ). , .

, , , , , . , GL ( JS).

+2

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