老實說，這聽起來像是 firefox 中的錯誤，盡管鑒于規(guī)范允許實現(xiàn)無法出于任何原因在畫布上提供模板緩沖區(qū)，但從技術上講這不是錯誤。我會考慮填一個。使用 Chromium 瀏覽器進行測試，以檢查這是 Firefox 選擇不提供模板緩沖區(qū)，而不是驅動程序問題或其他問題。
您應該能夠始終制作DEPTH_STENCIL渲染緩沖區(qū)。沒有允許實現(xiàn)不支持的 WebGL 版本。因此，您可以通過渲染到附加到幀緩沖區(qū)的紋理+深度模板渲染緩沖區(qū)來解決該錯誤，然后將幀緩沖區(qū)顏色紋理渲染到畫布。
這是一個測試。您應該會看到一個右下角為綠色的紅色正方形。那將在紫色方塊內(nèi)的藍色方塊內(nèi)。
藍色方塊用于顯示幀緩沖區(qū)紋理的范圍。如果綠色方塊沒有被模板緩沖區(qū)遮蓋，它就會滲入藍色。
紫色方塊顯示畫布的大小，我們繪制的幀緩沖區(qū)紋理小于整個畫布。這只是為了表明模板緩沖區(qū)可以在您的機器上工作。對于您自己的解決方案，您希望繪制一個由頂點組成的四邊形而不是使用如下所示的點，并且您希望使附加到幀緩沖區(qū)的紋理和渲染緩沖區(qū)與畫布的大小相同。
"use strict";
function main() {
const gl = document.querySelector("canvas").getContext("webgl");
const vs = `
attribute vec4 position;
"use strict";
function main() {
const gl = document.querySelector("canvas").getContext("webgl");
const vs = `
attribute vec4 position;
void main() {
gl_Position = position;
gl_PointSize = 64.0;
}
`;
const fs = `
precision mediump float;
uniform sampler2D tex;
void main() {
gl_FragColor = texture2D(tex, gl_PointCoord.xy);
}
`;
const program = twgl.createProgram(gl, [vs, fs]);
const posLoc = gl.getAttribLocation(program, "position");
// Create a texture to render to
const targetTextureWidth = 128;
const targetTextureHeight = 128;
const targetTexture = createTexture(gl);
{
// define size and format of level 0
const level = 0;
const internalFormat = gl.RGBA;
const border = 0;
const format = gl.RGBA;
const type = gl.UNSIGNED_BYTE;
const data = null;
gl.texImage2D(gl.TEXTURE_2D, level, internalFormat,
targetTextureWidth, targetTextureHeight, border,
format, type, data);
}
// Create and bind the framebuffer
const fb = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fb);
// attach the texture as the first color attachment
const attachmentPoint = gl.COLOR_ATTACHMENT0;
const level = 0;
gl.framebufferTexture2D(gl.FRAMEBUFFER, attachmentPoint, gl.TEXTURE_2D, targetTexture, level);
// create a depth-stencil renderbuffer
const depthStencilBuffer = gl.createRenderbuffer();
gl.bindRenderbuffer(gl.RENDERBUFFER, depthStencilBuffer);
// make a depth-stencil buffer and the same size as the targetTexture
gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, targetTextureWidth, targetTextureHeight);
gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
function createTexture(gl, color) {
const tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);
// set the filtering so we don't need mips
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
if (color) {
gl.texImage2D(
gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0,
gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(color));
}
return tex;
}
// create a red texture and a green texture
const redTex = createTexture(gl, [255, 0, 0, 255]);
const greenTex = createTexture(gl, [0, 255, 0, 255]);
gl.enable(gl.STENCIL_TEST);
gl.useProgram(program);
gl.clearColor(0, 0, 1, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.bindTexture(gl.TEXTURE_2D, redTex);
gl.stencilFunc(
gl.ALWAYS, // the test
1, // reference value
0xFF, // mask
);
gl.stencilOp(
gl.KEEP, // what to do if the stencil test fails
gl.KEEP, // what to do if the depth test fails
gl.REPLACE, // what to do if both tests pass
);
// draw a 64x64 pixel red rect in middle
gl.drawArrays(gl.POINTS, 0, 1);
gl.stencilFunc(
gl.EQUAL, // the test
1, // reference value
0xFF, // mask
);
gl.stencilOp(
gl.KEEP, // what to do if the stencil test fails
gl.KEEP, // what to do if the depth test fails
gl.KEEP, // what to do if both tests pass
);
// draw a green 64x64 pixel square in the
// upper right corner. The stencil will make
// it not go outside the red square
gl.vertexAttrib2f(posLoc, 0.5, 0.5);
gl.bindTexture(gl.TEXTURE_2D, greenTex);
gl.drawArrays(gl.POINTS, 0, 1);
// draw the framebuffer's texture to
// the canvas. we should see a 32x32
// red square with the bottom right corner
// green showing the stencil worked. That will
// be surrounded by blue to show the texture
// we were rendering to is larger than the
// red square. And that will be surrounded
// by purple since we're drawing a 64x64
// point on a 128x128 canvas which we clear
// purple.
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.clearColor(1, 0, 1, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.vertexAttrib2f(posLoc, 0.0, 0.0);
gl.bindTexture(gl.TEXTURE_2D, targetTexture);
gl.drawArrays(gl.POINTS, 0, 1);
}
main();
canvas { border: 1px solid black; }
<script src="https://twgljs.org/dist/4.x/twgl.min.js"></script>
<canvas width="128" height="128"></canvas>
void main() {
gl_Position = position;
gl_PointSize = 64.0;
}
`;
const fs = `
precision mediump float;
uniform sampler2D tex;
void main() {
gl_FragColor = texture2D(tex, gl_PointCoord.xy);
}
`;
const program = twgl.createProgram(gl, [vs, fs]);
const posLoc = gl.getAttribLocation(program, "position");
// Create a texture to render to
const targetTextureWidth = 128;
const targetTextureHeight = 128;
const targetTexture = createTexture(gl);
{
// define size and format of level 0
const level = 0;
const internalFormat = gl.RGBA;
const border = 0;
const format = gl.RGBA;
const type = gl.UNSIGNED_BYTE;
const data = null;
gl.texImage2D(gl.TEXTURE_2D, level, internalFormat,
targetTextureWidth, targetTextureHeight, border,
format, type, data);
}
// Create and bind the framebuffer
const fb = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fb);
// attach the texture as the first color attachment
const attachmentPoint = gl.COLOR_ATTACHMENT0;
const level = 0;
gl.framebufferTexture2D(gl.FRAMEBUFFER, attachmentPoint, gl.TEXTURE_2D, targetTexture, level);
// create a depth-stencil renderbuffer
const depthStencilBuffer = gl.createRenderbuffer();
gl.bindRenderbuffer(gl.RENDERBUFFER, depthStencilBuffer);
// make a depth-stencil buffer and the same size as the targetTexture
gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_STENCIL, targetTextureWidth, targetTextureHeight);
gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
function createTexture(gl, color) {
const tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);
// set the filtering so we don't need mips
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
if (color) {
gl.texImage2D(
gl.TEXTURE_2D, 0, gl.RGBA, 1, 1, 0,
gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(color));
}
return tex;
}
// create a red texture and a green texture
const redTex = createTexture(gl, [255, 0, 0, 255]);
const greenTex = createTexture(gl, [0, 255, 0, 255]);
gl.enable(gl.STENCIL_TEST);
gl.useProgram(program);
gl.clearColor(0, 0, 1, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.bindTexture(gl.TEXTURE_2D, redTex);
gl.stencilFunc(
gl.ALWAYS, // the test
1, // reference value
0xFF, // mask
);
gl.stencilOp(
gl.KEEP, // what to do if the stencil test fails
gl.KEEP, // what to do if the depth test fails
gl.REPLACE, // what to do if both tests pass
);
// draw a 64x64 pixel red rect in middle
gl.drawArrays(gl.POINTS, 0, 1);
gl.stencilFunc(
gl.EQUAL, // the test
1, // reference value
0xFF, // mask
);
gl.stencilOp(
gl.KEEP, // what to do if the stencil test fails
gl.KEEP, // what to do if the depth test fails
gl.KEEP, // what to do if both tests pass
);
// draw a green 64x64 pixel square in the
// upper right corner. The stencil will make
// it not go outside the red square
gl.vertexAttrib2f(posLoc, 0.5, 0.5);
gl.bindTexture(gl.TEXTURE_2D, greenTex);
gl.drawArrays(gl.POINTS, 0, 1);
// draw the framebuffer's texture to
// the canvas. we should see a 32x32
// red square with the bottom right corner
// green showing the stencil worked. That will
// be surrounded by blue to show the texture
// we were rendering to is larger than the
// red square. And that will be surrounded
// by purple since we're drawing a 64x64
// point on a 128x128 canvas which we clear
// purple.
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.clearColor(1, 0, 1, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.vertexAttrib2f(posLoc, 0.0, 0.0);
gl.bindTexture(gl.TEXTURE_2D, targetTexture);
gl.drawArrays(gl.POINTS, 0, 1);
}
main();
canvas { border: 1px solid black; }
<script src="https://twgljs.org/dist/4.x/twgl.min.js"></script>
<canvas width="128" height="128"></canvas>
如果將渲染緩沖區(qū)格式更改為 DEPTH_COMPONENT16 并將附著點更改為 DEPTH_ATTACHMENT，那么您將看到綠色方塊不再被模板遮蓋
您應該能夠調(diào)用gl.getContextAttributes以檢查您是否有模板緩沖區(qū)，因此如果它告訴您您沒有在畫布上獲得模板緩沖區(qū)，您可以使用建議的解決方案。
