| <html> |
| <head> |
| <script src="../../../resources/js-test.js"></script> |
| <script src="resources/webgl-test.js"></script> |
| <script id="vshader" type="x-shader/x-vertex"> |
| attribute vec3 g_Position; |
| |
| void main() |
| { |
| gl_Position = vec4(g_Position.x, g_Position.y, g_Position.z, 1.0); |
| } |
| </script> |
| |
| <script id="fshader" type="x-shader/x-fragment"> |
| void main() |
| { |
| gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); |
| } |
| </script> |
| |
| </head> |
| <body> |
| <canvas id="example" width="4px" height="4px"></canvas> |
| <div id="description"></div> |
| <div id="console"></div> |
| <script> |
| description('Verifies that GL viewport does not change when canvas is resized'); |
| |
| var gl = initWebGL("example", "vshader", "fshader", [ "g_Position" ], [ 0, 0, 1, 1 ], 1); |
| |
| var vertices = new Float32Array([ |
| 1.0, 1.0, 0.0, |
| -1.0, 1.0, 0.0, |
| -1.0, -1.0, 0.0, |
| 1.0, 1.0, 0.0, |
| -1.0, -1.0, 0.0, |
| 1.0, -1.0, 0.0]); |
| var vbo = gl.createBuffer(); |
| gl.bindBuffer(gl.ARRAY_BUFFER, vbo); |
| gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW); |
| |
| gl.enableVertexAttribArray(0); |
| gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0); |
| |
| // Clear and set up |
| gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); |
| gl.useProgram(gl.program); |
| // Draw the triangle pair to the frame buffer |
| gl.drawArrays(gl.TRIANGLES, 0, 6); |
| |
| // Ensure that the frame buffer is red at the sampled pixel |
| var buf = new Uint8Array(1 * 1 * 4); |
| gl.readPixels(2, 2, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf); |
| var passed = true; |
| if (buf[0] != 255 || |
| buf[1] != 0 || |
| buf[2] != 0 || |
| buf[3] != 255) { |
| testFailed("Pixel at (2, 2) should have been (255, 0, 0, 255), " + |
| "was (" + buf[0] + ", " + buf[1] + ", " + buf[2] + ", " + buf[3] + ")"); |
| passed = false; |
| } |
| |
| if (passed) { |
| // Now resize the canvas |
| var canvas = document.getElementById("example"); |
| canvas.width = 8; |
| canvas.height = 8; |
| // Do another render |
| gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); |
| gl.drawArrays(gl.TRIANGLES, 0, 6); |
| // This time, because we did not change the viewport, it should |
| // still be (0, 0, 4, 4), so only the lower-left quadrant should |
| // have been filled. |
| var buf = new Uint8Array(1 * 1 * 4); |
| gl.readPixels(6, 6, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf); |
| var passed = true; |
| if (buf[0] != 0 || |
| buf[1] != 0 || |
| buf[2] != 255 || |
| buf[3] != 255) { |
| testFailed("Pixel at (6, 6) should have been (0, 0, 255, 255), " + |
| "was (" + buf[0] + ", " + buf[1] + ", " + buf[2] + ", " + buf[3] + ")"); |
| passed = false; |
| } |
| } |
| |
| if (passed) |
| testPassed("Viewport correctly did not change size during canvas resize"); |
| </script> |
| </body> |
| </html> |
