Javascript Webgl在直线上应用1D纹理
我有一个webgl应用程序,其中有很多段(gl.LINES)。每个分段需要应用特定的1D纹理,或者如果愿意,分段的每个像素需要具有特定的颜色。这将用作线段上直方图的替代方案 我做了一个4像素的测试纹理,从红色到黑色。我希望看到从红色到黑色的渐变,但是输出是一条只有红色的线 以下是我的getTextureFromPixelArray方法:Javascript Webgl在直线上应用1D纹理,javascript,opengl-es,webgl,texture-mapping,Javascript,Opengl Es,Webgl,Texture Mapping,我有一个webgl应用程序,其中有很多段(gl.LINES)。每个分段需要应用特定的1D纹理,或者如果愿意,分段的每个像素需要具有特定的颜色。这将用作线段上直方图的替代方案 我做了一个4像素的测试纹理,从红色到黑色。我希望看到从红色到黑色的渐变,但是输出是一条只有红色的线 以下是我的getTextureFromPixelArray方法: Scene.getTextureFromPixelArray = function(data, width, height) { if (_.isArr
Scene.getTextureFromPixelArray = function(data, width, height) {
if (_.isArray(data) && data.length) {
var gl = this._context;
data = new Uint8Array(data);
var texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.pixelStorei(gl.UNPACK_ALIGNMENT, 1);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, data);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
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);
gl.bindTexture(gl.TEXTURE_2D, null);
return texture;
} else {
this.log("Unable to create texture");
}
return null;
};
以下是生成测试纹理1D的代码:
var verticles = [];
verticles.push(this.vertex1.position[0]);
verticles.push(this.vertex1.position[1]);
verticles.push(this.vertex2.position[0]);
verticles.push(this.vertex2.position[1]);
var color = [];
var textureWidth = 4;
var textureHeight = 1;
var textureCoords = [];
for (var i=0;i<textureHeight;i++) {
for (var j=0;j<textureWidth;j++) {
color.push(Math.round(255 - j*255/(textureWidth-1))); // Red
color.push(0); // Green
color.push(0); // Blue
color.push(255); // Alpha
}
}
textureCoords.push(0);
textureCoords.push(0.5);
textureCoords.push(1);
textureCoords.push(0.5);
var vertexPositionAttributeLocation = gl.getAttribLocation(shaderProgram, "aVertexPosition");
var textureCoordAttributeLocation = gl.getAttribLocation(shaderProgram, "aTextureCoord");
// Set vertex buffers
gl.enableVertexAttribArray(vertexPositionAttributeLocation);
var verticlesBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, verticlesBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(verticles), gl.STATIC_DRAW);
gl.vertexAttribPointer(vertexPositionAttributeLocation, 2, gl.FLOAT, false, 0, 0);
var texture = this.getTextureFromPixelArray(textureData, textureWidth, textureHeight||1);
var vertexTextureCoordBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexTextureCoordBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
gl.vertexAttribPointer(textureCoordAttributeLocation, 2, gl.FLOAT, false, 0, 0);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.uniform1i(gl.getUniformLocation(shaderProgram, "uSampler"), 0);
// Draw the segment
gl.drawArrays(gl.LINES, 0, verticles.length/2);
有人能看到我在哪里出错吗?我需要使用以下选项启用纹理坐标属性:
gl.enableVertexAttribArray(textureCoordAttributeLocation);
以前
var vertexTextureCoordBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexTextureCoordBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
gl.vertexAttribPointer(textureCoordAttributeLocation, 2, gl.FLOAT, false, 0, 0);
var vertexTextureCoordBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexTextureCoordBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
gl.vertexAttribPointer(textureCoordAttributeLocation, 2, gl.FLOAT, false, 0, 0);