I wrote a test suite using LWJGL and Clojure to test OpenGL rendering using frame buffers.The following program is supposed to render two quads into the frame buffer.See here for offscreen rendering implementation.
(def vertex-passthrough"#version 410 corein vec3 point;void main(){ gl_Position = vec4(point, 1);}")(def fragment-blue"#version 410 coreout vec3 fragColor;void main(){ fragColor = vec3(0.0, 0.0, 1.0);}")(def fragment-red"#version 410 coreout vec3 fragColor;void main(){ fragColor = vec3(1.0, 0.0, 0.0);}")(fact "Correct switching between two vertex array objects and shader programs" (offscreen-render 160 120 (let [indices [0 1 3 2] vertices1 [-1.0 -1.0 0.1, 0.5 -1.0 0.1, -1.0 0.5 0.1, 0.5 0.5 0.1] vertices2 [-0.5 -0.5 0.2, 1.0 -0.5 0.2, -0.5 1.0 0.2, 1.0 1.0 0.2] program1 (make-program :sfsim.render/vertex [vertex-passthrough] :sfsim.render/fragment [fragment-red]) program2 (make-program :sfsim.render/vertex [vertex-passthrough] :sfsim.render/fragment [fragment-blue]) vao1 (make-vertex-array-object program1 indices vertices1 ["point" 3]) vao2 (make-vertex-array-object program2 indices vertices2 ["point" 3])] (clear (vec3 0.0 0.0 0.0)) (use-program program1) (render-quads vao1) (use-program program2) (render-quads vao2) (destroy-vertex-array-object vao2) (destroy-vertex-array-object vao1) (destroy-program program2) (destroy-program program1))) => (is-image "test/sfsim/fixtures/render/objects.png" 0.0))On an AMD/ATI card I get the expected result:
However running the same test suite with NVidia GeForce RTX 2080 and proprietary drivers does not show the first (the red) quad:
Do you have any ideas what the problem could be?