/*
Copyright (c) 2019 The Khronos Group Inc.
Use of this source code is governed by an MIT-style license that can be
found in the LICENSE.txt file.
*/

function generateTest(internalFormat, pixelFormat, pixelType, prologue, resourcePath, defaultContextVersion) {
    var wtu = WebGLTestUtils;
    var tiu = TexImageUtils;
    var gl = null;
    var successfullyParsed = false;
    var imgCanvas;
    var redColor = [255, 0, 0];
    var greenColor = [0, 255, 0];

    function init()
    {
        description('Verify texImage2D and texSubImage2D code paths taking SVG image elements (' + internalFormat + '/' + pixelFormat + '/' + pixelType + ')');

        // Set the default context version while still allowing the webglVersion URL query string to override it.
        wtu.setDefault3DContextVersion(defaultContextVersion);
        gl = wtu.create3DContext("example");

        if (!prologue(gl)) {
            finishTest();
            return;
        }

        switch (gl[pixelFormat]) {
          case gl.RED:
          case gl.RED_INTEGER:
            greenColor = [0, 0, 0];
            break;
          case gl.LUMINANCE:
          case gl.LUMINANCE_ALPHA:
            redColor = [255, 255, 255];
            greenColor = [0, 0, 0];
            break;
          case gl.ALPHA:
            redColor = [0, 0, 0];
            greenColor = [0, 0, 0];
            break;
          default:
            break;
        }

        gl.clearColor(0,0,0,1);
        gl.clearDepth(1);

        wtu.loadTexture(gl, resourcePath + "red-green.svg", runTest);
    }

    function runOneIteration(image, useTexSubImage2D, flipY, topColor, bottomColor, bindingTarget, program)
    {
        debug('Testing ' + (useTexSubImage2D ? 'texSubImage2D' : 'texImage2D') +
              ' with flipY=' + flipY + ' bindingTarget=' +
              (bindingTarget == gl.TEXTURE_2D ? 'TEXTURE_2D' : 'TEXTURE_CUBE_MAP'));
        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
        // Disable any writes to the alpha channel
        gl.colorMask(1, 1, 1, 0);
        var texture = gl.createTexture();
        // Bind the texture to texture unit 0
        gl.bindTexture(bindingTarget, texture);
        // Set up texture parameters
        gl.texParameteri(bindingTarget, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
        gl.texParameteri(bindingTarget, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
        // Set up pixel store parameters
        gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
        gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
        wtu.failIfGLError(gl, 'gl.pixelStorei(gl.UNPACK_COLORSPACE_CONVERSION_WEBGL, gl.NONE);');
        var targets = [gl.TEXTURE_2D];
        if (bindingTarget == gl.TEXTURE_CUBE_MAP) {
            targets = [gl.TEXTURE_CUBE_MAP_POSITIVE_X,
                       gl.TEXTURE_CUBE_MAP_NEGATIVE_X,
                       gl.TEXTURE_CUBE_MAP_POSITIVE_Y,
                       gl.TEXTURE_CUBE_MAP_NEGATIVE_Y,
                       gl.TEXTURE_CUBE_MAP_POSITIVE_Z,
                       gl.TEXTURE_CUBE_MAP_NEGATIVE_Z];
        }
        // Upload the image into the texture
        for (var tt = 0; tt < targets.length; ++tt) {
            if (useTexSubImage2D) {
                // Initialize the texture to black first
                gl.texImage2D(targets[tt], 0, gl[internalFormat], image.width, image.height, 0,
                              gl[pixelFormat], gl[pixelType], null);
                gl.texSubImage2D(targets[tt], 0, 0, 0, gl[pixelFormat], gl[pixelType], image);
            } else {
                gl.texImage2D(targets[tt], 0, gl[internalFormat], gl[pixelFormat], gl[pixelType], image);
            }
        }

        var loc;
        if (bindingTarget == gl.TEXTURE_CUBE_MAP) {
            loc = gl.getUniformLocation(program, "face");
        }

        for (var tt = 0; tt < targets.length; ++tt) {
            if (bindingTarget == gl.TEXTURE_CUBE_MAP) {
                gl.uniform1i(loc, targets[tt]);
            }
            // Draw the triangles
            wtu.clearAndDrawUnitQuad(gl, [0, 0, 0, 255]);
            // Check a few pixels near the top and bottom and make sure they have
            // the right color.
            debug("Checking lower left corner");
            wtu.checkCanvasRect(gl, 4, 4, 2, 2, bottomColor,
                                "shouldBe " + bottomColor);
            debug("Checking upper left corner");
            wtu.checkCanvasRect(gl, 4, gl.canvas.height - 8, 2, 2, topColor,
                                "shouldBe " + topColor);
        }
    }

    function runTest(image)
    {
        var program = tiu.setupTexturedQuad(gl, internalFormat);
        runTestOnBindingTarget(image, gl.TEXTURE_2D, program);
        program = tiu.setupTexturedQuadWithCubeMap(gl, internalFormat);
        runTestOnBindingTarget(image, gl.TEXTURE_CUBE_MAP, program);

        wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors");
        finishTest();
    }

    function runTestOnBindingTarget(image, bindingTarget, program) {
        var cases = [
            { sub: false, flipY: true, topColor: redColor, bottomColor: greenColor },
            { sub: false, flipY: false, topColor: greenColor, bottomColor: redColor },
            { sub: true, flipY: true, topColor: redColor, bottomColor: greenColor },
            { sub: true, flipY: false, topColor: greenColor, bottomColor: redColor },
        ];
        for (var i in cases) {
            runOneIteration(image, cases[i].sub, cases[i].flipY,
                            cases[i].topColor, cases[i].bottomColor,
                            bindingTarget, program);
        }
    }

    return init;
}