A minamal example to reproduce a bug with glCopyImageSubData

repro_bug_glCopyImageSubData.cpp

#include <stdio.h>
#include <assert.h>
#include <stdint.h>
#include <SDL.h>
#include <glad/glad.h>

typedef uint32_t u32;

static const char* geGlErrStr(GLenum const err)
{
    switch (err) {
    case GL_NO_ERROR: return "GL_NO_ERROR";
    case GL_INVALID_ENUM: return "GL_INVALID_ENUM";
    case GL_INVALID_VALUE: return "GL_INVALID_VALUE";
    case GL_INVALID_OPERATION: return "GL_INVALID_OPERATION";
    case GL_OUT_OF_MEMORY: return "GL_OUT_OF_MEMORY";
    case GL_INVALID_FRAMEBUFFER_OPERATION: return "GL_INVALID_FRAMEBUFFER_OPERATION";
    default:
        assert(!"unknown error");
        return nullptr;
    }
}

static void glPostCallback(const char* name, void* funcptr, int len_args, ...)
{
    GLenum error_code;
    error_code = glad_glGetError();
    if (error_code != GL_NO_ERROR) {
        fprintf(stderr, "ERROR %s in %s\n", geGlErrStr(error_code), name);
        assert(false);
    }
}

static float initTexData[2][64][3];

int main(int argc, char* argv[])
{
    if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
        fprintf(stderr, "Error: %s\n", SDL_GetError());
        return -1;
    }
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);

    SDL_Window* window = SDL_CreateWindow("title",
        SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
        800, 600,
        SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE
    );

    SDL_GLContext glContext = SDL_GL_CreateContext(window);
    if (glContext == nullptr) {
        printf("Error creating GLES context\n");
    }
    SDL_GL_MakeCurrent(window, glContext);

    if (gladLoadGLLoader(SDL_GL_GetProcAddress) == 0) {
        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
        return -1;
    }
    glad_set_post_callback(glPostCallback);

    printf("Vendor:   %s\n", glGetString(GL_VENDOR));
    printf("Renderer: %s\n", glGetString(GL_RENDERER));
    printf("Version:  %s\n", glGetString(GL_VERSION));

    u32 tex0;
    glGenTextures(1, &tex0);
    glBindTexture(GL_TEXTURE_1D_ARRAY, tex0);
    glTexImage2D(GL_TEXTURE_1D_ARRAY, 0, GL_RGBA8, 64, 2, 0, GL_RGBA, GL_FLOAT, initTexData);
    glTexParameteri(GL_TEXTURE_1D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_1D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_1D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    u32 tex1;
    glGenTextures(1, &tex1);
    glBindTexture(GL_TEXTURE_1D_ARRAY, tex1);
    glTexImage2D(GL_TEXTURE_1D_ARRAY, 0, GL_RGBA8, 64, 3, 0, GL_RGBA, GL_FLOAT, nullptr);
    glTexParameteri(GL_TEXTURE_1D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_1D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_1D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glCopyImageSubData(
        tex0, GL_TEXTURE_1D_ARRAY,
        0, 0, 0, 0,
        tex1, GL_TEXTURE_1D_ARRAY,
        0, 0, 0, 0,
        64, 2, 1
    );

    printf("press any key to continue\n");
    getchar();
}